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﻿Title: Scientific American Supplement, No. 470, January 3, 1885
Author: Various
Language: English
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[Illustration]
SCIENTIFIC AMERICAN SUPPLEMENT NO. 470
NEW YORK, JANUARY 3, 1885
Scientific American Supplement. Vol. XIX, No. 470.
Scientific American established 1845
Scientific American Supplement, $5 a year.
Scientific American and Supplement, $7 a year.
* * * * *
TABLE OF CONTENTS.
I. METALLURGY, CHEMISTRY, ETC.--The Elasticity of Metals.
The Liquefaction of the Elementary Gases.--By JULES JAMIN.
Examination of Fats.
Notes on Nitrification.--By R. WARINGTON.--Paper read before
the British Association at Montreal.
II. ENGINEERING AND MECHANICS.--Flow of Water through
Hose Pipes.
Iron Pile Planks in the Construction of Foundations under
Water.--3 engravings.
Sound Signals.--Extracts from a paper by A.B. JOHNSON.--Treating
of gongs, guns, rockets, bells, whistling buoys, bell
buoys, locomotive whistles, trumpets, the siren, and the use of
natural orifices.--2 engravings.
Trevithick's High Pressure Engine at Crewe.--2 engravings.
Planetary Wheel Trains.--By Prof. C.W. MACCORD.--With a
page and a half of illustrations.
Bridge over the River Indus, at Attock. Punjaub, Northern State
Railway, India.--Full page illustrations.
The Harrington Rotary Engine.--3 figures.
III. TECHNOLOGY.--Testing Car Varnishes.--By D.D. ROBERTSON.
Aniline Dyes in Dress Materials.--By Prof. CHAS. O'NEILL.
IV. DECORATIVE ART.--A. Chippendale Sideboard.--With engraving.
V. PHYSICS, MAGNETISM, ETC.--The Fallacy of the Present
Theory of Sound.--Abstract of a lecture by Dr. H.A. MOTT.
The Fixation of Magnetic Phantoms.--With engraving.
VI. NATURAL HISTORY.--Researches on the Origin and Life Histories
of the Least and Lowest Living Things---By Rev. W.H.
DALLINGER.
VII. MEDICINE, ETC.--Case of Resuscitation and Recovery after
Apparent Death by Hanging.--by Dr. E.W. WHITE.
VIII. MISCELLANEOUS.--The Inventors' Institute.--Address of the
Chairman at the opening of the twenty-second session of the
Institute, October 2.
The New Central School at Paris.--3 engravings.
* * * * *
FLOW OF WATER THROUGH HOSE PIPES.
At a recent meeting in this city of the American Society of Civil
Engineers, a paper by Edmund B. Weston was read, giving the description
and result of experiments on the flow of water through a 2½ inch hose and
through nozzles of various forms and sizes; also giving the results of
experiments as to the height of jets of water. The experiments were made
at Providence, R.I. The water was taken from a hydrant to the head of
which were attached couplings holding two pressure gauges, and from the
couplings the hose extended to a tank holding 2,100 gallons, so arranged
as to measure accurately the time and amount of delivery of water by the
hose. Different lengths of hose were used. The experiments resulted in the
following formula for flow from coupling:
1. For hose between 90 and 100 feet in length, and where great accuracy is
required:
---------------------------------------------------
/ 2gh
V = / ---------------------------------------------------
/ / 0.504 \
\/ 1 - 0.0256d^{4} + ( 0.0087 + ------- ) 0.12288d^{4}l.
\ --- /
\/ v
[TEX: V = \sqrt{\frac{2gh}{1 - 0.0256 d^4 + (0.0087 +
\frac{0.504}{\sqrt{v}}) 0.12288 d^4 l}}.]
2. For all lengths of hose, a reliable general formula:
----------------------------------------------
/ h
V = / ----------------------------------------------
\/ 0.0155463 - 0.000398d^{4} + 0.0000362962d^{4}l.
[TEX: V = \sqrt{\frac{h}{0.0155463 - 0.000398 d^4 + 0.0000362962 d^4 l}}.]
g being velocity of efflux in feet per second.
h, head in feet indicated by gauge.
d, of coupling in inches.
l, length of hose in feet from gauge.
v, velocity in 2½ inch hose.
Forty-five experiments were made on ring nozzles, resulting in the
following formula:
f = 0.001135v².
f being loss of head in feet owing to resistance of nozzle, and v the
velocity of the contracted vein in feet per second.
Thirty-five experiments were made with smooth nozzles, resulting in the
following formula:
f = 0.0009639 v².
f being the loss of head in feet owing to resistance, and v the
velocity of efflux in feet per second.
Experiments show that a prevailing opinion is incorrect that jets will
rise higher from ring nozzles than from smooth nozzles.
Box's formula for height of jets of water compares very favorably with
experimental results.
* * * * *
IRON PILE PLANKS IN THE CONSTRUCTION OF FOUNDATIONS UNDER WATER.
The annexed engravings illustrate a method of constructing subaqueous
foundations by the use of iron pile planks. These latter, by reason of
their peculiar form, present a great resistance, not only to the vertical
blow of the pile driver (as it is indispensable that they should), but
also to horizontal pressure when excavating is being done or masonry being
constructed within the space which they circumscribe. Polygonal or curved
perimeters may be circumscribed with equal facility by joining the piles,
the sides of one serving as a guide to that of its neighbor, and special
pieces being adapted to the angles. Preliminary studies will give the
dimensions, form, and strength of the iron to be employed. The latter, in
fact, will be rolled to various thicknesses according to the application
to be made of it. We may remark that the strength of the iron, aside from
that which is necessary to allow the pile to withstand a blow in a
vertical direction, will not have to be calculated for all entire
resistance to the horizontal pressure due to a vacuum caused by the
excavation, for the stiffness of the piles may be easily maintained and
increased by establishing string-pieces and braces in the interior in
measure as the excavation goes on.
[Illustration: FIG. 1.--CONSTRUCTION OF A DOCK WALL BEHIND PAPONOTS IRON
PILE PLANKS.]
The system is applicable to at least three different kinds of work: (1)
The making of excavations with a dredge and afterward concreting without
pumping out the water. (2) The removal of earth or the construction of
masonry under protection from water (Fig. 1). (3) The making of
excavations by dredging and afterward concreting without pumping, mid
then, after the beton has set, pumping out the water in order to continue
the masonry in the open air. This construction of masonry in the open air
has the great advantage of allowing the water to evaporate from the
mortar, and consequently of causing it to dry and effect a quick and
perfect cohesion of the materials employed.
[Illustration: FIG. 2.--TRAVERSE SECTION OF TWO PILES CONNECTED BY MORTAR
JOINTS.]
This system may likewise be employed with advantage for the forming of
stockades in rivers, or for building sea walls. A single row of pile
planks will in many cases suffice for the construction of dock walls in
the river or ocean when the opposite side is to be filled in, or in any
other analogous case (Fig. 1).
The piles are driven by means of the ordinary apparatus in use. Their
heads are covered with a special apparatus to prevent them from being
flattened out under the blows of the pile driver. They may be made in a
single piece or be composed of several sections connected together with
rivets. They are designed according to circumstances, to be left in the
excavation in order to protect the masonry, or to be removed in their
entirety or in parts, as is done with caissons. In case they are to remain
wholly or in part in the excavation, they are previously galvanized or
painted with an inoxidizable coating in order to protect them and increase
their durability.
The points of the piles, whatever be their form and arrangement, are
strengthened by means of steel pieces, which assure of their penetrating
hard and compact earth.
[Illustration: FIG. 3.--DREDGING WITHIN A SPACE CIRCUMSCRIBED BY IRON PILE
PLANKS.]
Fig. 2 represents a dredge at work within a space entirely circumscribed
by pile planks. Here, after the excavation is finished, beton will be put
down by means of boxes with hinged bottoms, and the water will afterward
be pumped out in order to allow the masonry to be constructed in the open
air. Fig. 3 shows a transverse section of two of these pile planks united
by mortar joints. This system is the invention of Mr. Papenot.--_Revue
Industrielle._
* * * * *
AN ATMOSPHERIC BATTERY.
Great ingenuity is being shown in the arrangement of new forms of primary
batteries. The latest is that devised by M. Jablochkoff, which acts by the
effect of atmospheric moisture upon the metal sodium. A small rod of this
metal is flattened into a plate, connected at one end to a copper wire.
There is another plate of carbon, not precisely the same as that used for
arc lights or ordinary batteries, but somewhat lighter in texture. This
plate is perforated, and provided with small wooden pegs. The sodium plate
is wrapped in silk paper, and pressed upon the carbon in such a manner
that the wooden pegs penetrate the soft sodium. For greater security the
whole is tied together with a few turns of fine iron wire; care being
taken that the wire does not form an electric contact between the sodium
and the carbon. The element is then complete, the carbon and the small
copper wire being the electrodes. The sodium, on exposure to the air,
becomes oxidized, forming caustic soda, which with the moisture of the air
dissolves, and drains gradually away in the form of a concentrated
solution; thus constantly exposing the fresh surface of the metal, which
renders the reaction continuous. The price of the element is lower than
would be expected at first sight from the employment of so expensive a
metal. The present cost of sodium is 10 frs. per kilogramme; but M.
Jablochkoff thinks that on the large scale the metal might be obtained at
a very low figure. The elements are grouped in sets of ten, hung upon rods
in such a manner that the solution as formed may drain off. Such a battery
continues in action as long as the air contains moisture; the only means
of stopping it is to shut it up in an air-tight case. The electro-motive
force depends on the degree of humidity in the air, and also upon the
temperature.
* * * * *
ANALYSIS OF PERFUMED SCOURING PASTES.--The analysis of No. 1 resulted in
water and traces of myrbane oil, 3.66 per cent.; fatty acid, melting at
104° F., 54.18 per cent.; iron peroxide, 10.11 per cent.; silicic acid,
14.48 per cent.; alumina, 17.31 per cent.; lime and magnesia, traces. The
iron peroxide is partly soluble in hydrochloric acid, the alumina entirely
so as silicate. The scouring paste, therefore, is composed of 54 per cent.
fatty (palm oil) acid, 10 per cent. jeweler's rouge, 32 per cent.
pumice-stone powder.
* * * * *
SOUND SIGNALS.
In Appleton's "Annual Cyclopædia" for 1883, Mr. Arnold B. Johnson, Chief
Clerk of the Lighthouse Board, contributes a mass of very interesting
information, under the above title. His descriptions of the most approved
inventions relating thereto are interesting, and we make the following
extracts:
The sound signals generally used to guide mariners, especially during
fogs, are, with certain modifications, sirens, trumpets, steam-whistles,
bell-boats, bell-buoys, whistling buoys, bells struck by machinery,
cannons fired by powder or gun cotton, rockets, and gongs.
_Gongs._--Gongs are somewhat used on lightships, especially in British
waters. They are intended for use at close quarters. Leonce Reynaud, of
the French lighthouse service, has given their mean effective range as
barely 550 yards. They are of most use in harbors, short channels, and
like places, where a long range would be unnecessary. They have been used
but little in United States waters. The term "effective range" is used
here to signify the actual distance at which, under the most unfavorable
circumstances, a signal can generally be heard on board of a paddle-wheel
steamer in a heavy sea-way.
_Guns._--The use of guns is not so great as it once was. Instances are on
record in which they were quite serviceable. Admiral Sir A. Milne said he
had often gone into Halifax harbor, in a dense fog like a wall, by the
sound of the Sambro fog gun. But in the experiments made by the Trinity
House off Dungeness in January, 1864, in calm weather, the report of an
eighteen-pounder, with three pounds of powder, was faint at four miles.
Still, in the Trinity House experiments of 1865, made in light weather
with a light gun, the report was clearly heard seven miles away. Dr.
Gladstone records great variability in the range of gun-sound in the
Holyhead experiments. Prof. Henry says that a twenty-four-pounder was used
at Point Boneta, San Francisco Bay, Cal., in 1856-57, and that, by the
help of it alone, vessels came into the harbor during the fog at night as
well as in the day, which otherwise could not have entered. The gun was
fired every half hour, night and day, during foggy and thick weather in
the first year, except for a time when powder was lacking. During the
second year there were 1,582 discharges. It was finally superseded by a
bell-boat, which in its turn was after a time replaced by a siren. A gun
was also used at West Quoddy Head, Maine. It was a carronade, five feet
long, with a bore of five and one-quarter inches, charged with four pounds
of powder. The gun was fired on foggy days when the Boston steamer was
approaching the lighthouse from St. Johns, and the firing was begun when
the steamer's whistle was heard, often when she was six miles away, and
was kept up as fast as the gun could be loaded, until the steamer answered
with its whistle.
The report of the gun was heard from two to six miles. "This signal was
abandoned," Prof. Henry says, "because of the danger attending its use,
the length of intervals between successive explosions, and the brief
duration of the sound, which renders it difficult to determine its
direction with accuracy." In 1872 there were three fog guns on the English
coast, iron eighteen-pounders, carrying a three pound charge of powder,
which were fired at intervals of fifteen minutes in two places, and of
twenty minutes in the other. The average duration of fog at these stations
was said to be about six hours, and as it not unfrequently lasted twenty
hours, each gun required two gunners, who had to undergo severe labor, and
the risk of remissness and irregularity was considerable. In 1881 the
interval between charges was reduced to ten minutes.
The Trinity House, in its experiments at South Foreland, found that the
short twenty-four pound howitzer gave a better sound than the long
eighteen-pounder. Tyndall, who had charge of the experiments, sums up as
to the use of the guns as fog-signals by saying: "The duration of the
sound is so short that, unless the observer is prepared beforehand, the
sound, through lack of attention rather than through its own
powerlessness, is liable to be unheard. Its liability to be quenched by
local sound is so great that it is sometimes obliterated by a puff of wind
taking possession of the ears at the time of its arrival. Its liability to
be quenched by an opposing wind, so as to be practically useless at a very
short distance to windward, is very remarkable.... Still, notwithstanding
these drawbacks, I think the gun is entitled to rank as a first-class
signal."
The minute gun at sea is known the world over as a signal of distress. The
English lightships fire guns to attract the attention of the lifeboat crew
when shipwrecks take place in sight of the ships, but out of sight of the
boats; and guns are used as signals of approaching floods at freshet times
in various countries.
_Rockets._--As a signal in rock lighthouses, where it would be impossible
to mount large pieces of apparatus, the use of a gun-cotton rocket has
been suggested by Sir Richard Collinson, deputy-master of the Trinity
House. A charge of gun-cotton is inclosed in the head of a rocket, which
is projected to the height of perhaps 1,000 feet, when the cotton is
exploded, and the sound shed in all directions. Comparative experiments
with the howitzer and rocket showed that the howitzer was beaten by a
rocket containing twelve ounces, eight ounces, and even four ounces of
gun-cotton. Large charges do not show themselves so superior to small
charges as might be expected. Some of the rockets were heard at a distance
of twenty-five miles. Tyndall proposes to call it the Collinson rocket,
and suggests that it might be used in lighthouses and lightships as a
signal by naval vessels.
_Bells._--Bells are in use at every United States lightstation, and at
many they are run by machinery actuated by clock-work, made by Mr.
Stevens, of Boston, who, at the suggestion of the Lighthouse Board, has
introduced an escapement arrangement moved by a small weight, while a
larger weight operates the machinery which strikes the bell. These bells
weigh from 300 to 3,000 pounds. There are about 125 in use on the coasts
of the United States. Experiments made by the engineers of the French
Lighthouse Establishment, in 1861-62, showed that the range of bell-sounds
can be increased with the rapidity of the bell-strokes, and that the
relative distances for 15, 25, and 60 bell-strokes a minute were in the
ratio of 1, 1-14/100, and 1-29/100. The French also, with a hemispherical
iron reflector backed with Portland cement, increased the bell range in
the ratio of 147 to 100 over a horizontal arc of 60°, beyond which its
effect gradually diminished. The actual effective range of the bell sound,
whatever the bell size, is comparatively short, and, like the gong, it is
used only where it needs to be heard for short distances. Mr. Cunningham,
Secretary of the Scottish Lighthouse Establishment, in a paper on fog
signals, read in February, 1863, says the bell at Howth, weighing 2¼ tons,
struck four times a minute by a 60 pound hammer falling ten inches, has
been heard only one mile to windward against a light breeze during fog;
and that a similar bell at Kingston, struck eight times a minute, had been
so heard three miles away as to enable the steamer to make her harbor from
that distance. Mr. Beaseley, C.E., in a lecture on coast-fog signals, May
24, 1872, speaks of these bells as unusually large, saying that they and
the one at Ballycottin are the largest on their coasts, the only others
which compare with them being those at Stark Point and South Stack, which
weigh 31¾ cwt. and 41½ cwt. respectively. Cunningham, speaking of the
fog-bells at Bell Rock and Skerryvore lighthouses, says he doubts if
either bell has been the means of saving a single vessel from wreck during
fog, and he does not recall an instance of a vessel reporting that she was
warned to put about in the fog, or that she ascertained her position in
any respect by hearing the sound of the bell in either place. Gen. Duane,
U.S.A., says a bell, whether operated by hand or machinery, cannot be
considered an efficient fog signal on the sea-coast. In calm weather it
cannot be heard half the time at a greater distance than one mile, while
in rough weather the noise of the surf will drown its sound to seaward
altogether. The use of bells is required, by the International Code, on
ships of all nations, at regular intervals during fog. But Turkish ships
are allowed to substitute the gong or gun, as the use of bells is
forbidden to the followers of Mohammed.
[Illustration: FIG. 1.--COURTENAY'S WHISTLING BUOY.]
_Whistling Buoys._--The whistling buoy now in use was patented by Mr. J.M.
Courtenay, of New York. It consists of an iron pear-shaped bulb, 12 feet
across at its widest part, and floating 12 feet out of water. Inside the
bulb is a tube 33 inches across, extending from the top through the bottom
to a depth of 32 feet, into water free from wave motion. The tube is open
at its lower end, but projects, air-tight, through the top of the bulb,
and is closed with a plate having in it three holes, two for letting the
air into the tube, and one between the others for letting the air out to
work the 10-inch locomotive whistle with which it is surmounted. These
holes are connected with three pipes which lead down to near the water
level, where they pass through a diaphragm which divides the outer
cylinder into two parts. The great bulb which buoys up the whole mass
rises and falls with the motion of the waves, carrying the tube up and
down with it, thus establishing a piston-and-cylinder movement, the water
in the tube acting as an immovable piston, while the tube itself acts as a
moving cylinder. Thus the air admitted through valves, as the buoy rises
on the wave, into that part of the bulb which is above water, is
compressed, and as the buoy falls with the wave, it is further compressed
and forced through a 2½ inch pipe which at its apex connects with the
whistle. The dimensions of the whistling buoy have recently been much
diminished without detracting materially from the volume of sound it
produces. It is now made of four sizes. The smallest in our waters has a
bulb 6 feet in diameter and a tube 10 feet in length, and weighs but 2,000
pounds. The largest and oldest whistling buoy has a 12-foot bulb, a tube
32 feet long, and weighs 12,000 pounds.
There are now 34 of these whistling buoys on the coast of the United
States, which have cost, with their appurtenances, about $1,200 each. It
is a curious fact that, in proportion as they are useful to the mariner,
they are obnoxious to the house dweller within earshot of them, and that
the Lighthouse Board has to weigh the petitions and remonstrances before
setting these buoys off inhabited coasts. They can at times be heard 15
miles, and emit an inexpressibly mournful and saddening sound.
The inspector of the First Lighthouse District, Commander Picking,
established a series of observations at all the light stations in the
neighborhood of the buoys, giving the time of hearing it, the direction of
the wind, and the state of the sea, from which it appears that in January,
1878, one of these buoys was heard every day at a station 1-1/8 miles
distant, every day but two at one 2¼ miles distant, 14 times at one 7½
miles distant, and 4 times at one 8½ miles distant. It is heard by the
pilots of the New York and Boston steamers at a distance of one-fifth of a
mile to 5 miles, and has been frequently heard at a distance of 9 miles,
and even, under specially favorable circumstances, 15 miles.
The whistling buoy is also used to some extent in British, French, and
German waters, with good results. The latest use to which it has been put
in this country has been to place it off the shoals of Cape Hatteras,
where a light ship was wanted but could not live, and where it does
almost as well as a light ship would have done. It is well suited for such
broken and turbulent waters, as the rougher the sea the louder its sound.
[Illustration: FIG. 2.--BROWN'S BELL BUOY.]
_Bell-Buoys._--The bell-boat, which is at most a clumsy contrivance,
liable to be upset in heavy weather, costly to build, hard to handle, and
difficult to keep in repair, has been superseded by the Brown bell-buoy,
which was invented by the officer of the lighthouse establishment whose
name it bears. The bell is mounted on the bottom section of an iron buoy 6
feet 6 inches across, which is decked over and fitted with a framework of
3-inch angle-iron 9 feet high, to which a 300-pound bell is rigidly
attached. A radial grooved iron plate is made fast to the frame under the
bell and close to it, on which is laid a free cannon-ball. As the buoy
rolls on the sea, this ball rolls on the plate, striking some side of the
bell at each motion with such force as to cause it to toll. Like the
whistling-buoy, the bell-buoy sounds the loudest when the sea is the
roughest, but the bell-buoy is adapted to shoal water, where the
whistling-buoy could not ride; and, if there is any motion to the sea, the
bell-buoy will make some sound. Hence the whistling-buoy is used in
roadsteads and the open sea, while the bell-buoy is preferred in harbors,
rivers, and the like, where the sound-range needed is shorter, and
smoother water usually obtains. In July, 1883, there were 24 of these
bell-buoys in United States waters. They cost, with their fitments and
moorings, about $1,000 each.
_Locomotive-Whistles._--It appears from the evidence given in 1845, before
the select committee raised by the English House of Commons, that the use
of the locomotive-whistle as a fog-signal was first suggested by Mr. A.
Gordon, C.E., who proposed to use air or steam for sounding it, and to
place it in the focus of a reflector, or a group of reflectors, to
concentrate its sounds into a powerful phonic beam. It was his idea that
the sharpness or shrillness of the whistle constituted its chief value.
And it is conceded that Mr. C.L. Daboll, under the direction of Prof.
Henry, and at the instance of the United States Lighthouse Board, first
practically used it as a fog-signal by erecting one for use at Beaver Tail
Point, in Narragansett Bay. The sounding of the whistle is well described
by Price-Edwards, a noted English lighthouse engineer, "as caused by the
vibration of the column of air contained within the bell or dome, the
vibration being set up by the impact of a current of steam or air at a
high pressure." It is probable that the metal of the bell is likewise set
in vibration, and gives to the sound its timbre or quality. It is noted
that the energy so excited expends its chief force in the immediate
vicinity of its source, and may be regarded, therefore, as to some extent
wasted. The sound of the whistle, moreover, is diffused equally on all
sides. These characteristics to some extent explain the impotency of the
sound to penetrate to great distances. Difference in pitch is obtained by
altering the distance between the steam orifice and the rim of the drum.
When brought close to each other, say within half an inch, the sound
produced is very shrill, but it becomes deeper as the space between the
rim and the steam or air orifice is increased.
Prof. Henry says the sound of the whistle is distributed horizontally. It
is, however, much stronger in the plane containing the lower edge of the
bell than on either side of this plane. Thus, if the whistle is standing
upright in the ordinary position, its sound is more distinct in a
horizontal plane passing through the whistle than above it or below it.
The steam fog-whistle is the same instrument ordinarily used on steamboats
and locomotives. It is from 6 to 18 inches in diameter, and is operated by
steam under a pressure of from 50 to 100 pounds. An engine takes its steam
from the same boiler, and by an automatic arrangement shuts off and turns
on the steam by opening and closing its valves at determined times. The
machinery is simple, the piston-pressure is light, and the engine requires
no more skilled attention than does an ordinary station-engine.
"The experiments made by the Trinity House in 1873-74 seem to show,"
Price-Edwards says, "that the sound of the most powerful whistle, whether
blown by steam or hot air, was generally inferior to the sound yielded by
other instruments," and consequently no steps were taken to extend their
use in Great Britain, where several were then in operation. In Canadian
waters, however, a better result seems to have been obtained, as the
Deputy Minister of Marine and Fisheries, in his annual report for 1872,
summarizes the action of the whistles in use there, from which it appears
that they have been heard at distances varying with their diameter from 3
to 25 miles.
The result of the experiments made by Prof. Henry and Gen. Duane for the
United States Lighthouse Board, reported in 1874, goes to show that the
steam-whistle could be heard far enough for practical uses in many
positions. Prof. Henry found that he could hear a 6-inch whistle 7¼ miles
with a feeble opposing wind. Gen. Duane heard the 10-inch whistle at Cape
Elizabeth at his house in Portland, Maine, nine miles distant, whenever it
was in operation. He heard it best during a heavy northeast snow storm,
the wind blowing then directly from him, and toward the source of the
sound. Gen. Duane also reported that "there are six fog-signals on the
coast of Maine; these have frequently been heard at the distance of twenty
miles," ... which distance he gives as the extreme limit of the
twelve-inch steam-whistle.
_Trumpets._--The Daboll trumpet was invented by Mr. C.L. Daboll, of
Connecticut, who was experimenting to meet the announced wants of the
United States Lighthouse Board. The largest consists of a huge trumpet
seventeen feet long, with a throat three and one-half inches in diameter,
and a flaring mouth thirty-eight inches across. In the trumpet is a
resounding cavity, and a tongue-like steel reed ten inches long, two and
three-quarter inches wide, one inch thick at its fixed end, and half that
at its free end. Air is condensed in a reservoir and driven through the
trumpet by hot air or steam machinery at a pressure of from fifteen to
twenty pounds, and is capable of making a shriek which can be heard at a
great distance for a certain number of seconds each minute, by about
one-quarter of the power expended in the case of the whistle. In all his
experiments against and at right angles and at other angles to the wind,
the trumpet stood first and the whistle came next in power. In the trial
of the relative power of various instruments made by Gen. Duane in 1874,
the twelve-inch whistle was reported as exceeding the first-class Daboll
trumpet. Beaseley reports that the trumpet has done good work at various
British stations, making itself heard from five to ten miles. The engineer
in charge of the lighthouses of Canada says: "The expense for repairs, and
the frequent stoppages to make these repairs during the four years they
continued in use, made them [the trumpets] expensive and unreliable. The
frequent stoppages during foggy weather made them sources of danger
instead of aids to navigation. The sound of these trumpets has
deteriorated during the last year or so." Gen. Duane, reporting as to his
experiments in 1881, says: "The Daboll trumpet, operated by a caloric
engine, should only be employed in exceptional cases, such as at stations
where no water can be procured, and where from the proximity of other
signals it may be necessary to vary the nature of the sound." Thus it
would seem that the Daboll trumpet is an exceptionally fine instrument,
producing a sound of great penetration and of sufficient power for
ordinary practical use, but that to be kept going it requires skillful
management and constant care.
_The Siren._--The siren was adapted from the instrument invented by
Cagniard de la Tour, by A. and F. Brown, of the New York City Progress
Works, under the guidance of Prof. Henry, at the instance and for the use
of the United States Lighthouse Establishment, which also adopted it for
use as a fog-signal. The siren of the first class consists of a huge
trumpet, somewhat of the size and shape used by Daboll, with a wide mouth
and a narrow throat, and is sounded by driving compressed air or steam
through a disk placed in its throat. In this disk are twelve radial slits;
back of the fixed disk is a revolving plate, containing as many similar
openings. The plate is rotated 2,400 times each minute, and each
revolution causes the escape and interruption of twelve jets of air or
steam through the openings in the disk and rotating plate. In this way
28,800 vibrations are given during each minute that the machine is
operated; and, as the vibrations are taken up by the trumpet, an intense
beam of sound is projected from it. The siren is operated under a pressure
of seventy-two pounds of steam, and can be heard, under favorable
circumstances, from twenty to thirty miles. "Its density, quality, pitch,
and penetration render it dominant over such other noises after all other
signal-sounds have succumbed." It is made of various sizes or classes, the
number of slits in its throat-disk diminishing with its size. The
dimensions given above are those of the largest. [See engraving on page
448, "Annual Cyclopædia" for 1880.]
The experiments made by Gen. Duane with these three machines show that the
siren can be, all other things being equal, heard the farthest, the
steam-whistle stands next to the siren, and the trumpet comes next to the
whistle. The machine which makes the most noise consumes the most fuel.
From the average of the tests it appears that the power of the first-class
siren, the twelve-inch whistle, and first-class Daboll trumpet are thus
expressed: siren nine, whistle seven, trumpet four; and their relative
expenditure of fuel thus: siren nine, whistle three, trumpet one.
Sound-signals constitute so large a factor in the safety of the navigator,
that the scientists attached to the lighthouse establishments of the
various countries have given much attention to their production and
perfection, notably Tyndall in England and Henry in this country. The
success of the United States has been such that other countries have sent
commissions here to study our system. That sent by England in 1872, of
which Sir Frederick Arrow was chairman, and Captain Webb, R.N., recorder,
reported so favorably on it that since then "twenty-two sirens have been
placed at the most salient lighthouses on the British coasts, and sixteen
on lightships moored in position where a guiding signal is of the greatest
service to passing navigation."
The trumpet, siren, and whistle are capable of such arrangement that the
length of blast and interval, and the succession of alternation, are such
as to identify the location of each, so that the mariner can determine his
position by the sounds.
In this country there were in operation in July, 1883, sixty-six
fog-signals operated by steam or hot air, and the number is to be
increased in answer to the urgent demands of commerce.
_Use of Natural Orifices._--There are, in various parts of the world,
several sound-signals made by utilizing natural orifices in cliffs through
which the waves drive the air with such force and velocity as to produce
the sound required. One of the most noted is that on one of the Farallon
Islands, forty miles off the harbor of San Francisco, which was
constructed by Gen. Hartmann Bache, of the United States Engineers, in
1858-59, and of which the following is his own description:
"Advantage was taken of the presence of the working party on the island to
make the experiment, long since contemplated, of attaching a whistle as a
fog-signal to the orifice of a subterranean passage opening out upon the
ocean, through which the air is violently driven by the beating of the
waves. The first attempt failed, the masonry raised upon the rock to which
it was attached being blown up by the great violence of the wind-current.
A modified plan with a safety-valve attached was then adopted, which it is
hoped will prove permanent. ... The nature of this work called for 1,000
bricks and four barrels of cement."
Prof. Henry says of this:
"On the apex of this hole he erected a chimney which terminated in a tube
surmounted by a locomotive-whistle. By this arrangement a loud sound was
produced as often as the wave entered the mouth of the indentation. The
penetrating power of the sound from this arrangement would not be great if
it depended merely on the hydrostatic pressure of the waves, since this
under favorable circumstances would not be more than that of a column of
water twenty feet high, giving a pressure of about ten pounds to the
square inch. The effect, however, of the percussion might add considerably
to this, though the latter would be confined in effect to a single
instance. In regard to the practical result from this arrangement, which
was continued in operation for several years, it was found not to obviate
the necessity of producing sounds of greater power. It is, however,
founded on an ingenious idea, and may be susceptible of application in
other cases."
There is now a first-class siren in duplicate at this place.
The sixty-six steam fog-signals in the waters of the United States have
been established at a cost of more than $500,000, and are maintained at a
yearly expense of about $100,000. The erection of each of these signals
was authorized by Congress in an act making special appropriations for its
establishment, and Congress was in each instance moved thereto by the
pressure of public opinion, applied usually through the member of Congress
representing the particular district in which the signal was to be
located. And this pressure was occasioned by the fact that mariners have
come to believe that they could be guided by sound as certainly as by
sight. The custom of the mariner in coming to this coast from beyond the
seas is to run his ship so that on arrival, if after dark, he shall see
the proper coast-light in fair weather, and, if in thick weather, that he
shall hear fog-signal, and, taking that as a point of departure, to feel
his way from the coast-light to the harbor-light, or from the fog-signal
on the coast to the fog-signal in the harbor, and thence to his anchorage
or his wharf. And the custom of the coaster or the sound-steamer is
somewhat similar.
* * * * *
TREVITHICK'S ENGINE AT CREWE.
The old high-pressure engine of Richard Trevithick, which, thanks to Mr.
Webb, has been rescued from a scrap heap in South Wales, and re-erected at
the Crewe Works. We give engravings of this engine, which have been
prepared from photographs kindly furnished to us by Mr. Webb, and which
will clearly show its design.
[Illustration: TREVITHICK'S HIGH PRESSURE ENGINE AT CREWE.]
The boiler bears a name-plate with the words "No. 14, Hazeldine and Co.,
Bridgnorth," and it is evidently one of the patterns which Trevithick was
having made by Hazeldine and Co., about the year 1804. The shell of the
boiler is of cast iron, and the cylinder, which is vertical, is cast in
one with it, the back end of the boiler and the barrel being in one piece
as shown. At the front end the barrel has a flange by means of which it is
bolted to the front plate, the plate having attached to it the furnace and
return flue, which are of wrought iron. The front plate has also cast on
it a manhole mouthpiece to which the manhole cover is bolted. In the case
of the engine at Crewe, the chimney, firehole door, and front of flue had
to be renewed by Mr. Webb, these parts having been broken up before the
engine came into his possession.
The piston rod is attached to a long cast-iron crosshead, from which two
bent connecting rods extend downward, the one to a crank, and the other to
a crank-pin inserted in the flywheel. The connecting-rods now on this
engine were supplied by Mr. Webb, the original ones--which they have been
made to resemble as closely as possible--having been broken up. In the
Crewe engine as it now exists it is not quite clear how the power was
taken off from the crankshaft, but from the particulars of similar engines
recorded in the "Life of Richard Trevithick," it appears that a small spur
pinion was in some cases fixed on the crankshaft, and in others a
spurwheel, with a crank-pin inserted in it, took the place of the crank at
the end of the shaft opposite to that carrying the flywheel. In the Crewe
engine the flywheel, it will be noticed, is provided with a balanceweight.
The admission of the steam to and its release from the cylinder is
effected by a four-way cock provided with a lever, which is actuated by a
tappet rod attached to the crosshead, as seen on the back view of the
engine. To the crosshead is also coupled a lever having its fulcrum on a
bracket attached to the boiler; this lever serving to work the feed pump.
Unfortunately the original pump of the Crewe engine was smashed, but Mr.
Webb has fitted one up to show the arrangement. A notable feature in the
engine is that it is provided with a feed heater through which the water
is forced by the pump on its way to the boiler. The heater consists of a
cast-iron pipe through which passes the exhaust pipe leading from the
cylinder to the chimney, the water circulating through the annular space
between the two pipes.
Altogether the Trevithick engine at Crewe is a relic of the very highest
interest, and it is most fortunate that it has come into Mr. Webb's hands
and has thus been rescued from destruction. No one, bearing in mind the
date at which it was built, can examine this engine without having an
increased respect for the talents of Richard Trevithick, a man to whom we
owe so much and whose labors have as yet met with such scant
recognition.--_Engineering._
* * * * *
[Continued from SCIENTIFIC AMERICAN SUPPLEMENT, No. 451, page 7192.]
PLANETARY WHEEL TRAINS.
By Prof. C.W. MacCORD, Sc. D.
IV.
The arrangement of planetary wheels which has been applied in practice to
the greatest extent and to the most purposes, is probably that in which
the axial motions of the train are derived from a fixed sun wheel.
Numerous examples of such trains are met with in the differential gearing
of hoisting machines, in portable horse-powers, etc. The action of these
mechanisms has already been fully discussed; it may be remarked in
addition that unless the speed be very moderate, it is found advantageous
to balance the weights and divide the pressures by extending the train arm
and placing the planet-wheels in equal pairs diametrically opposite each
other, as, for instance, in Bogardus' horse power, Fig. 31.
[Illustration: PLANETARY WHEEL TRAINS.]
In trains of this description, the velocity ratio is invariable; which for
the above-mentioned objects it should be. But the use of a planetary
combination enables us to cause the motions of two independent trains to
converge, and unite in producing a single resultant rotation. This may be
done in two ways; each of the two independent trains may drive one
sun-wheel, thus determining the motion of the train-arm; or, the train-arm
may be driven by one of them, and the first sun-wheel by the other; then
the motion of the second sun-wheel is the resultant. Under these
circumstances the ratio of the resultant velocity to that of either
independent train is not invariable, since it may be affected by a change
in the velocity of the other one. To illustrate our meaning, we give two
examples of arrangements of this nature. The first is Robinson's
rope-making machine, Fig. 32. The bobbins upon which the strands composing
the rope are wound turn freely in bearings in the frames, G, G, and these
frames turn in bearings in the disk, H, and the three-armed frame or
spider, K, both of which are secured to the central shaft, S. Each
bobbin-frame is provided with a pinion, _a_, and these three pinions
engage with the annular wheel, A. This wheel has no shaft, but is carried
and kept in position by three pairs of rollers, as shown, so that its axis
of rotation is the same as that of the shaft, S; and it is toothed
externally as well as internally. The strands pass through the hollow
axes of the pinions, and thence each to its own opening through the
laying-top, T, fixed upon S, which completes the operation of twisting
them into a rope. The annular wheel, A, it will be perceived, may be
driven by a pinion, E, engaging with its external teeth, at a rate of
speed different from that of the central shaft; and by varying the speed
of that pinion, the velocity of the wheel, A, may be changed without
affecting the velocity of S.
It is true that in making a certain kind of rope, the velocity ratio of A
and S must remain constant, in order that the strands may be equally
twisted throughout; but if for another kind of rope a different degree of
twist is wanted, the velocity of the pinion, E, may be altered by means of
change-wheels, and thus the same machine may be used for manufacturing
many different sorts.
The second combination of this kind was devised by the writer as a
"tell-tale" for showing whether the engines driving a pair of twin
screw-propellers were going at the same rate. In Fig. 33, an index, P, is
carried by the wheel, F: the wheel, A, is loose upon the shaft of the
train-arm, which latter is driven by the wheel, E. The wheels, F and _f_,
are of the same size, but _a_ is twice as large as A; if then A be driven
by one engine, and E by the other, at the same rate but in the opposite
direction, the index will remain stationary, whatever the absolute
velocities. But if either engine go faster than the other, the index will
turn to the right or the left accordingly. The same object may also be
accomplished as shown in Fig. 34, the index being carried by the
train-arm. It makes no difference what the actual value of the ratio A/_a_
may be, but it must be equal to F/_f_: under which condition it is evident
that if A and F be driven contrary ways at equal speeds, small or great,
the train-arm will remain at rest; but any inequality will cause the index
to turn.
In some cases, particularly when annular wheels are used, the train-arm
may become very short, so that it may be impossible to mount the
planet-wheel in the manner thus far represented, upon a pin carried by a
crank. This difficulty may be surmounted as shown in Fig. 35, which
illustrates an arrangement originally forming a part of Nelson's steam
steering gear. The Internal pinions, _a_, _f_, are but little smaller than
the annular wheels, A, F, and are hung upon an eccentric E formed in one
solid piece with the driving shaft, D.
The action of a complete epicyclic train involves virtually and always the
action of two suns and two planets; but it has already been shown that the
two planets may merge into one piece, as in Fig. 10, where the
planet-wheel gears externally with one sun-wheel, and internally with the
other.
But the train may be reduced still further, and yet retain the essential
character of completeness in the same sense, though composed actually of
but two toothed wheels. An instance of this is shown in Fig. 36, the
annular planet being hung upon and carried by the pins of three cranks,
_c_, _c_, _c_, which are all equal and parallel to the virtual train-arm,
T. These cranks turning about fixed axes, communicate to _f_ a motion of
circular translation, which is the resultant of a revolution, _v'_, about
the axis of F in one direction, and a rotation, _v_, at the same rate in
the opposite direction about its own axis, as has been already explained.
The cranks then supply the place of a fixed sun-wheel and a planet of
equal size, with an intermediate idler for reversing the, direction of the
rotation of the planet; and the velocity of F is
V'= v'(1 - f/F).
A modification of this train better suited for practical use is shown in
Fig. 37, in which the sun-wheel, instead of the planet, is annular, and
the latter is carried by the two eccentrics, E, E, whose throw is equal to
the difference between the diameters of the two pitch circles; these
eccentrics must, of course, be driven in the same direction and at equal
speeds, like the cranks in Fig. 36.
[Illustration: PLANETARY WHEEL TRAINS.]
A curious arrangement of pin-gearing is shown in Fig. 38: in this case the
diameter of the pinion is half that of the annular wheel, and the latter
being the driver, the elementary hypocycloidal faces of its teeth are
diameters of its pitch circle; the derived working tooth-outlines for pins
of sensible diameter are parallels to these diameters, of which fact
advantage is taken to make the pins turn in blocks which slide in straight
slots as shown. The formula is the same as that for Fig. 36, viz.:
V' = v'(1 - f/F),
which, since f = 2F, reduces to V' = -v'.
Of the same general nature is the combination known as the "Epicycloidal
Multiplying Gear" of Elihu Galloway, represented in Fig. 39. Upon
examination it will be seen, although we are not aware that attention has
previously been called to the fact, that this differs from the ordinary
forms of "pin gearing" only in this particular, viz., that the elementary
tooth of the driver consists of a complete branch, instead of a
comparatively small part of the hypocycloid traced by rolling the smaller
pitch-circle within the larger. It is self-evident that the hypocycloid
must return into itself at the point of beginning, without crossing: each
branch, then, must subtend an aliquot part of the circumference, and can
be traced also by another and a smaller describing circle, whose diameter
therefore must be an aliquot part of the diameter of the outer
pitch-circle; and since this last must be equal to the sum of the
diameters of the two describing circles, it follows that the radii of the
pitch circles must be to each other in the ratio of two successive
integers; and this is also the ratio of the number of pins to that of the
epicycloidal branches.
Thus in Fig. 39, the diameters of the two pitch circles are to each other
as 4 to 5; the hypocycloid has 5 branches, and 4 pins are used. These pins
must in practice have a sensible diameter, and in order to reduce the
friction this diameter is made large, and the pins themselves are in the
form of rollers. The original hypocycloid is shown in dotted line, the
working curve being at a constant normal distance from it equal to the
radius of the roller; this forms a sort of frame or yoke, which is hung
upon cranks as in Figs. 36 and 38. The expression for the velocity ratio
is the same as in the preceding case:
V¹ = v'(1 - f/F); which in Fig. 39 gives
V¹ = v'(1 - 5/4)= -¼v':
the planet wheel, or epicycloidal yoke, then, has the higher speed, so
that if it be desired to "gear up," and drive the propeller faster than
the engine goes (and this, we believe, was the purpose of the inventor),
the pin-wheel must be made the driver; which is the reverse of
advantageous in respect to the relative amounts of approaching and
receding action.
In Figs. 40 and 41 are given the skeletons of Galloway's device for ratios
of 3:4 and 2:3 respectively, the former having four branches and three
pins, the latter three branches and two pins. Following the analogy, it
would seem that the next step should be to employ two branches with only
one pin; but the rectilinear hypocycloid of Fig. 38 is a complete
diameter, and the second branch is identical with the first; the straight
tooth, then, could theoretically drive the pin half way round, but upon
its reaching the center of the outer wheel, the driving action would
cease: this renders it necessary to employ two pins and two slots, but it
is not essential that the latter should be perpendicular to each other.
In these last arrangements, the forms of the parts are so different from
those of ordinary wheels, that the true nature of the combinations is at
least partially disguised. But it may be still more completely hidden, as
for instance in the common elliptic trammel, Fig. 42. The slotted cross is
here fixed, and the pins, R and P, sliding respectively in the vertical
and horizontal lines, control the motion of the bar which carries the
pencil, S. At first glance there would seem to be nothing here resembling
wheel works. But if we describe a circle upon R P as a diameter, its
circumference will always pass through C, because R C P is a right angle,
and the instantaneous axis of the bar being at the intersection O of a
vertical line through P, with a horizontal line through R, will also lie
upon this circumference. Again, since O is diametrically opposite to C, we
have C O = R P, whence a circle about center C with radius R P will also
pass through O, which therefore is the point of contact of these two
circles. It will now be seen that the motion of the bar is the same as
though carried by the inner circle while rolling within the outer one, the
latter being fixed; the points P and R describing the diameters L M and K
N, the point D a circle, and S an ellipse; C D being the train-arm. The
distance R P being always the diameter of one circle and the radius of the
other, the sizes of the wheels can be in effect varied by altering that
distance.
Thus we see that this combination is virtually the same in its action as
the one shown in Fig. 43, known as Suardi's Geometrical Pen. In this
particular case the diameter of _a_ is half of that of A; these wheels are
connected by the idler, E, which merely reverses the direction without
affecting the velocity of _a's_ rotation. The working train arm is jointed
so as to pivot about the axis of E, and may be clamped at any angle within
its range, thus changing the length of the virtual train arm, C D. The bar
being fixed to _a_, then, moves as though carried by the wheel, _a¹_,
rolling within A¹; the radius of _a¹_ being C D, and that of A¹ twice as
great.
In either instrument, the semi-major axis C X is equal to S R, and the
semi-minor axis to S P.
The _ellipse_, then, is described by these arrangements because it is a
special form of the epitrochoid; and various other epitrochoids may be
traced with Suardi's pen by substituting other wheels, with different
numbers of teeth, for a in Fig. 43.
Another disguised planetary arrangement is found in Oldham's coupling,
Fig. 44. The two sections of shafting, A and B, have each a flange or
collar forged or keyed upon them; and in each flange is planed a
transverse groove. A third piece, C, equal in diameter to the flanges, is
provided on each side with a tongue, fitted to slide in one of the
grooves, and these tongues are at right angles to each other. The axes of
A and B must be parallel, but need not coincide; and the result of this
connection is that the two shafts will turn in the same direction at the
same rate.
The fact that C in this arrangement is in reality a planetary wheel, will
be perceived by the aid of the diagram, Fig. 45. Let C D be two pieces
rotating about fixed parallel axes, each having a groove in which slides
freely one of the arms, A C, A D, which are rigidly secured to each other
at right angles.
The point C of the upper arm can at the instant move only in the direction
C A; and the point D of the lower arm only in the direction A D, at the
same instant; the instantaneous axis is therefore at the intersection, K,
of perpendiculars to A C and A D, at the points C and D. C A D K being
then a rectangle, A K and C D will be two diameters of a circle whose
center, O, bisects C D; and K will also be the point of contact between
this circle and another whose center is A, and radius A K = C D. If then
we extend the arms so as to form the cross, P K, M N, and suppose this to
be carried by the outer circle, _f_, rolling upon the inner one, F, its
motion will be the same as that determined by the pieces, C D; and such a
cross is identical with that formed by the tongues on the coupling-piece,
C, of Fig. 44.
A O is the virtual train-arm; let the center, A, of the cross move to the
position B, then since the angles A O B at the center, and A C B in the
circumference, stand on the same arc, A B, the former is double the
latter, showing that the cross revolves twice round the center O during
each rotation of C; and since A C B = A D B, C and D rotate with equal
velocities, and these rotations and the revolution about O have the same
direction. While revolving, the cross rotates about its traveling center,
A, in the opposite direction, the contact between the two circles being
internal, and at a rate equal to that of the rotations of C and D, because
the velocities of the axial and the orbital motion are to each other as
_f_ is to F, that is to say, as 1 is to 2. Since in the course of the
revolution the points P and K must each coincide with C, and the points M
and N with D, it follows that each tongue in Fig. 44 must slide in its
groove a distance equal to twice that between the axes of the shafts.
Another example of a disguised planetary train is shown in Fig. 46. Let C
be the center about which the train arm, T, revolves, and suppose it
required that the distant shaft, B, carried by T, shall turn once backward
for each forward revolution of the arm. E is a fixed eccentric of any
convenient diameter, in the upper side of which is a pin, D. On the shaft,
B, is keyed a crank, B G, equal in length to C D; and at any convenient
point, H, on B C, or its prolongation, another crank, H F, equal also to C
D, is provided with a bearing in the train-arm. The three crank pins, F,
D, G, are connected by a rod, like the parallel rod of a locomotive; F D,
D G, being respectively equal to H C, C B. Then, as the train-arm
revolves, the three cranks must remain parallel to each other; but C D
being fixed, the cranks, H F and B G, will remain always parallel to their
original positions, thus receiving the required motion of circular
translation.
The result then is the same as though the periphery of E were formed into
a fixed spurwheel, A, and another, _a_, of the same size, secured on a
shaft, B, the two being connected by the three equal wheels, L, M, N. It
need hardly be stated that instead of the eccentric, E, a stationary crank
similar and equal to B G may be used, should it be found better suited to
the circumstances of the case.
It is possible also to apply the planetary principle to mechanism composed
partially of racks; in fact, a rack is merely a wheel of prodigious
size--the limiting case, just as a right line is a circle of infinite
radius. A very neat application of this principle is found in Villa's
Pantograph, of which a full description and illustration was given in
SCIENTIFIC AMERICAN SUPPLEMENT, No. 424; the racks, moving side by side,
are the sun-wheels, and the planet-wheels are the pinions, carried by the
traveling socket, by which the motion of one rack is transmitted to the
other.
Thus far attention has been called only to combinations of circular
wheels. In these the velocity ratios are constant, if we except the cases
in which two independent trains converge, the two sun-wheels, or one of
them and the train-arm, being driven separately--and even in those, a
variable motion of the ultimate follower is obtained only by varying the
speed of one or both drivers. It is not, however, necessary to employ
circular wheels exclusively or even at all; wheels of other forms are
capable of acting together in the relation of sun and planet, and in this
way a varying velocity ratio may be produced even with a fixed sun-wheel
and a single driver. We have not found, in the works of any previous
writer, any intimation that noncircular wheels have ever been thus
combined; and we propose in the following article to illustrate some
curious results which may be thus obtained.
* * * * *
THE FALLACY OF THE PRESENT THEORY OF SOUND.
Dr. H.A. Mott recently delivered a lecture before the New York Academy of
Sciences, in Columbia College, on the Fallacy of the Present Theory of
Sound.
He commenced his lecture by stating that "the object of science was not to
find out what we like or what we dislike; the object of science was
truth." He then said that, as Galileo stated a hypothesis should be judged
by the weight of facts and the force of mathematical deductions, he
claimed the theory of sound should be so examined, and not allowed to
exist as a true theory simply because it is sustained by a long line of
scientific names; as too many theories had been overthrown to warrant the
acceptance of any one authority unless they had been thoroughly tested.
Dr. Mott stated that Dr. Wilford Hall was the first to attack the theory
of sound and show its fallaciousness, and that many other scientists
besides himself had agreed with Dr. Hall in his arguments and had advanced
additional arguments and experiments to establish this fact. Dr. Mott
first gave a very elaborate and still at the same time condensed statement
of the current theory of sound as propounded by such men as Helmholtz,
Tyndall, Lord Rayleigh, Mayer, Rood, Sir Wm. Thomson, and others, and
closed this section of the paper with the remarks made by Tyndall:
"Assuredly no question of science ever stood so much in need of revision
as this of the transmission of sound through the atmosphere. Slowly but
surely we mastered the question, and the further we advance, the more
plainly it appeared that our reputed knowledge regarding it was erroneous
from beginning to end."
Dr. Mott then took up the other side of the question, and treated the same
under the following heads:
1. Agitation of the air. 2. Mobility of the atmosphere. 3. Resonance. 4.
Heat and velocity of the supposed sound waves. 5. Decrease in loudness of
sound. 6. The physical strength of the locust. 7. The barometric theory of
Sir Wm. Thomson. 8. Elasticity and density of the air. 9. Interference and
beats. 10. The membrana tympani and the corti arches.
Under the first head Dr. Mott stated that all experiments and photographs
made to establish the existence of sound waves simply referred to the
necessary agitation of the air accompanying any disturbance, such as would
of necessity be produced by a vibrating body, and had nothing to do
directly with sound. He stated that in the Edison telephone, sound was
converted directly into electricity without vibrating any diaphragm at
all, as attested to by Edison himself. Speaking of the mobility of the
air, he said the particles were free to slip around and not practically be
pushed at all, and that the greatest distance a steam whistle could affect
the air would not exceed 30 feet, and the waves would not travel more than
4 or 5 feet a second, while sound travels 1,120 feet a second. Under heat
and velocity of sound waves, Dr. Mott stated that Newton found by
calculating the exact relative density and elasticity of air that sound
should travel only 916 feet a second, while it was known to travel 1,120
feet a second.
Laplace, by a heat and cold theory, tried to account for the 174 feet, and
supposed that in the condensed portion of a sound wave heat was generated,
and in the rarefied portion cold was produced; the heat augmenting the
elasticity and therefore the sound waves, and the cold produced
neutralizing the heat, thus kept the atmosphere at a constant temperature.
Dr. Mott stated that when Newton first pointed out this discrepancy of 174
feet, the theory should have been dropped at once, and later on he showed
the consequences of Laplace's heat and cold theory.
The great argument of the evening, and the one to which he attached the
most importance, was that all scientists have spoken of the swift movement
of the tuning fork, while in fact it moved 25,000 times slower than the
hour hand of a clock and 300,000,000 times slower than any clock pendulum
ever constructed.
Since a pendulum cannot, according to the high authorities, produce
sonorous air waves on account of its slow movement, Dr. Mott asks some one
to enlighten him how a prong of a tuning fork going 300,000,000 times
slower could be able to produce them. He then showed that there was not
the slightest similarity between the theoretical sound waves and water
waves, and still they are spoken of as "precisely similar" and
"essentially identical," and "move in exactly the same way." Considerable
merriment was occasioned when Dr. Mott showed what a locust stridulating
in the air would be called upon to do if the present theory of sound were
correct. He stated that a locust not weighing more than half a
pennyweight, and that could not move an ounce weight, was supposed capable
of setting 4 cubic miles of atmosphere into vibration, weighing
120,000,000 tons, so that it would be displaced 440 times in one second,
and any portion of the air could bend the human tympanic membrane once in
and once out 440 times in one second; and that 40,000,000 people, nearly
the whole population of the United States, could have their 5,000 pounds
of tympanic membrane thus shaken by an insect that could not move an ounce
weight to save its life; and that the 231,222 pounds of tympanic membrane
of the entire population of the earth, amounting to 1,350,000,000, who
could conveniently stand in 11¼ square miles, would be affected the same
way by 34 locusts stridulating in the air. According to the barometric
theory of Sir William Thomson, he showed that a locust would have to add
60,000,000 pounds to the weight of the atmosphere.
Under elasticity and density he stated that elasticity was a mere property
of a body, and could not add one grain of force to that exercised by the
locust, so as to assist it in performing such wonderful feats. Under
interference he showed that the law of interference is fallacious; that no
such thing occurs; and that in the experiment with the siren to show such
fact, the octave is produced which of necessity ought to be when the
number of orifices are alternately doubled, and the same effect would be
produced with one disk with double the number of holes. Under the last
head of his paper Dr. Mott proved that the membrana tympani was not
necessary for good hearing, that in fact when it was punctured, a deaf man
could in many cases be made to hear, and in fact it improved the hearing
in general; the only reason why the tympanic membrane was not punctured
oftener was that dust, heat, and cold were apt to injure the middle ear.
In closing his paper Dr. Mott said that he would risk the fallacy of the
current theory of sound on the argument advanced relating to the
impossibility of the slow motion of a tuning fork to produce sonorous
waves, and stated that he would retire if any one could show the fallacy
of the argument; but if not, the wave theory must be abandoned as absurd
and fallacious, as was the Ptolemaic system of astronomy, which was handed
down from age to age until Copernicus and his aide de camp Galileo gave to
the world a better system.
* * * * *
THE ATTOCK BRIDGE.
We give illustrations from _Engineering_ of a bridge recently constructed
across the Indus River at Attock, for the Punjaub Northern State Railway.
This bridge, which was opened on May 24, 1883, was erected under the
direction of Mr. F.L. O'Callaghan, engineer in chief, Mr. H. Johnson
acting as executive engineer, and Messrs. R.W. Egerton and H. Savary as
assistants.
[Illustration: BRIDGE OVER THE RIVER INDUS AT ATTOCK: PUNJAUB NORTHERN
STATE RAILWAY, INDIA.]
The principal spans cover a length of about 1,150 feet. It will be seen
from the diagram that there is a difference of nearly 100 feet in the
levels of high and low water.
* * * * *
THE ELASTICITY OF METALS.
M. Tresca has contributed to the _Comptes Rendus_ some observations on the
effect of hammering, and the variation of the limit of elasticity of
metals and materials used in the arts.
He says that hitherto, in considering the deformation of solids under
strain, two distinct periods, relative to their mechanical properties,
have alone been recognized. These periods are of course the elastic limit
and the breaking point. In the course of M. Tresca's own experiments,
however, he has found it necessary to consider, at the end of the period
of alteration of elasticity, a third state, geometrically defined and
describable as a period of fluidity, corresponding to the possibility of a
continuous deformation under the constant action of the same strain. This
particular condition is only realized with very malleable or plastic
bodies; and it may even be regarded as characteristic of such bodies,
since its absence is noticeable in all non-malleable or fragile bodies,
which break without being deformed. It is already known that the period of
altered elasticity for hard or tempered steel is much less than for iron.
In 1871 the author showed that steel or iron rails that had acquired a
permanent set were at the same time perfectly elastic up to the limit of
the load which they had already borne. With certain bars the same result
was renewed five times in succession; and thus their period of perfect
elasticity could be successively extended, while the coefficient of
elasticity did not appear to sustain any appreciable modification. This
process of repeated straining, when there is an absence of a certain
hammering effect, renders malleable bodies somewhat similar to those which
are not malleable and brittle. There is an indication here of another
argument against the testing of steam boilers by exaggerated pressures
before use, which process has the effect of rendering the plates more
brittle and liable to sudden rupture.
M. Tresca also protests against the elongation of metals under breaking
strain tests being stated as a percentage of the length. The elongation is
in all cases, chiefly local; and is therefore the same for a test piece
12 inches or 8 inches long, being confined to the immediate vicinity of
the point of rupture. The indication of elasticity should rather be sought
for in the reduction of the area of the bar at the point of rupture. This
portion of the bar is otherwise remarkable for having lost its original
condition. It is condensed in a remarkable manner, and has almost
completely lost its malleability. The final rupture, therefore, is that of
a brittle zone of the metal, of the same character that may be produced by
hammering. If a test bar, strained almost to the verge of rupture, be
annealed, it will stretch yet further before breaking; and, indeed, by
successive annealings and stretchings, may be excessively modified in its
proportions.
* * * * *
THE HARRINGTON ROTARY ENGINE.
The chief characteristic or principle of this engine is the maintenance of
an accurate steam and mechanical balance and the avoidance of cross
pressure. The power is applied directly to the work, the only friction
being that of the steel shaft in phosphor-bronze bearings. Referring to
the cuts, Fig. 1 shows the engine and an electric dynamo on the same
shaft, all connecting mechanism being done away with, and pounding
obviated. There are but two parts to the engine (two disks which supply
the place of all the ordinary mechanism), both of which are large, solid,
and durable. These disks have a bearing surface of several inches on each
other, preventing the passage of steam between them--a feature peculiar to
this engine. Fig. 2 represents an end elevation partly in section, showing
the piston, A, and the abutment disk, B, in the position assumed in the
instant of taking steam through a port from the valve-chamber, E. Fig. 3
is a vertical section through the center of Fig. 2, showing the relations
of the disks, C, and the abutment disks, B, and gear. The piston disks and
gear are attached to the driving shaft, H, and the abutment disks and gear
are attached to the shaft, K. These shafts, H and K, as above stated, run
in taper phosphor-bronze bearings, which are adjustable for wear or other
causes by the screw-caps, O. The whole mechanism is kept rigidly in place
by the flanged hub, r, bolted securely to the cylinder head, F. These
flanged heads project through the cylinder head, touching the piston disk,
and thereby prevent any end motion of the shaft, H, or its attachments.
The abutment disks and shaft are furnished with similar inwardly
projecting flanged hubs, which are provided with a recess, I, Fig. 2, on
their periphery, located radially between the shaft, K, and the clearance
space, J. Into this recess steam is admitted--through an inlet in the
cylinder head not shown in the cuts. By this means the shaft, K, is
relieved of all side pressure. The exhaust-port, which is very large and
relieves all back pressure, is shown at D. The pistons and disks are made
to balance at the speed at which the engine is intended to run. The
steam-valve, for which patent is pending, is new in principle. It has a
uniform rotating motion, and, like the engine, is steam and mechanically
balanced. The governor is located in the flywheel, and actuates the
automatic cut-off, with which it is directly connected, without the
intervention of an eccentric, in such a way as to vary the cut-off without
changing the point of admission. By this means is secured uniformity of
motion under variable loads with variable boiler pressure. It also secures
the advantage resulting from high initial and low terminal pressure with
small clearances and absence of compression, giving a large proportionate
power and smooth action.
Expansion has been excellently provided for, the steam passing entirely
around before entering the cylinder. These engines are mounted on a
bed-plate which may be set on any floor without especial preparation
therefor. The parts are all made interchangeable. A permanent indicator is
provided which shows the exact point of cut-off. The steam-port is
exceptionally large, being one-fourth of the piston area. Reciprocating
motion is entirely done away with. The steam is worked at the greatest
leverage of the crank through the entire stroke. Among the other chief
advantages claimed for this engine are direct connection to the machinery
without belts, etc., impossibility of getting out of line, uniform crank
leverage, capacity for working equally well slow or fast, etc. It has but
one valve, which is operated by gear from the shaft, as shown, traveling
at one-half the velocity of the piston.
[Illustration: Fig. 1.--THE HARRINGTON ROTARY ENGINE COUPLED TO A DYNAMO.]
With this engine a speed of 5,000 revolutions per minute is easily
attainable, while, as a matter of fact and curiosity, a speed of 8,000
revolutions per minute has been obtained. An engine of this class was run
at the Illinois Inter-State Exposition at Chicago for six weeks at a
uniform speed of 1,050 revolutions per minute, furnishing the power for
twenty-three electric arc lights, with a steam pressure not exceeding
fifty-five pounds per square inch, and cutting off at from one-tenth to
one-sixth of the stroke. It was taking steam from a large main-pipe, so
there was no opportunity for an exact test of the amount of fuel used, but
from a careful mathematical calculation it must have been developing one
horse-power from three pounds of coal.
The inventor claims that, as his engine works the steam expansively, even
better results would have been obtained had the engine been furnished
steam at 100 pounds per square inch.
[Illustration: Figs. 2 and 3.--DETAILS OF HARRINGTON ENGINE.]
The Harrington Rotary Engine Company, 123 Clinton Street, Chicago, are the
owners and manufacturers.
* * * * *
In a can of peas sold in Liverpool recently the public analyst found two
grains of crystallized sulphate of copper, a quantity sufficient to
injuriously affect human health. The defendant urged that the public
insisted upon having green peas; and that artificial means had to be
resorted to to secure the required color.
* * * * *
TESTING CAR VARNISHES.
By D.D. ROBERTSON.
At the Master Car-Painters' Convention, D.D. Robertson, of the Michigan
Central, read the following paper on the best method of testing varnishes
to secure the most satisfactory results as to their durability, giving
practical suggestions as to the time a car may safely remain in the
service before being taken in for revarnishing:
The subject which the association has assigned to me for this convention
has always been regarded as important. There is no branch of the business
which gives the painter more anxiety than the varnishing department. It is
more susceptible to an endless variety of difficulties, and therefore
needs more close and careful attention, than all other branches put
together, and even with all the research and practical experience which
has been given to the subject we are yet far from coming to a definite
conclusion as to the causes of many of the unfavorable results.
Beauty and durability are what we aim at in the paint shop, and from my
experience in varnish work we may have beauty without durability, but we
have rarely durability without beauty, so that the fewer defects of any
kind in our work caused by inferior material, inferior workmanship, or any
other cause, it is more likely to be durable, and ought, therefore, to
possess beauty. There are certain qualifications absolutely necessary to
durability in varnish. The material of which it is made must be of the
proper kind, pure and unadulterated; the manipulation in manufacturing
must be correct as to time, quantities, temperature, handling, etc., and
age is also necessary. The want of durability arising from the quality of
the materials, or from the manner of manufacturing, the painter has no
control over; but let me say here, that frequently a first-class varnish
has been used upon a car, and after being in service for a short time it
deadens, checks, cracks, chips, or flakes, and therefore shows a very poor
record. The varnish is condemned, when in reality, had the varnish been
applied under different circumstances and over different work, the result
would have been good and the durability satisfactory.
I am satisfied that in many cases first-class varnish has to bear the
odium, when the root of the evil is to be found nearer the foundation. The
leading varnish manufacturers of this country have expended large fortunes
to secure the best skill and appliances, and, indeed, to do everything to
bring their goods to perfection. Their standing and respectability put
them beyond suspicion, and their reputation is of too much value for them
knowingly to put into the hands of large consumers an inferior article;
and even when we have just cause to complain of the varnish, we ought to
be charitable enough to attribute the mistake to circumstances beyond
their control (for every kettleful is subjected to such circumstances),
and not to charge them with using cheap or inferior material for the sake
of gain.
If the question which has been given me means to give some method of
testing before using, I confess my inability to answer. For varnish to be
pronounced "durable" must be composed of the materials to make it so, and
to ascertain this, chemistry must be called in to test it. Comparatively
few painters understand chemistry sufficiently to analyze, and if they
did, and found the material all that is necessary, the manipulation may
have been defective, so as to injure its wearing qualities, and therefore
I cannot suggest any way of pronouncing varnish durable before using it.
As to the common custom of hanging out boards prepared and varnished to
the exposure of the sun and weather for months does not seem to me to be
the correct way of testing durability. It is true we may by this mode get
some idea of wearing properties, but the most thorough and correct way is
to put the varnish to the same exposure, the tear and wear, that it would
have in the regular service on the road on which it is to run. Cars while
running are exposed to circumstances which boards on the wall are not
subjected to. The cars under my charge run through two different countries
and three different States, and therefore subjected to such a variety of
climate and soil that the testing by stationary boards would completely
fail to give the correct result. For example: I have placed two sample
boards, prepared and varnished, and exposed them to all kinds of weather
and to the constant and steady rays of the sun for an equal length of
time, and both gave favorable results; and I have also put the same
varnishes on a car and found very different results. One of the varnishes
having some properties adapted to resist the friction caused by cinders,
sand, and dust, and consequently not so liable to cut the surface, and
therefore much more durable.
The system which I adopted long ago, and to which I still adhere (not on
account of "old fogyism," but for want of better), is as follows: I have
two varnishes which I want to put into competition to test their relative
merits. With varnish No. 1, I do the south half of the east end of the car
and the east half of the south side of the car, the north half of the west
end, and also the west end of the north side; this is also done with the
same varnish. On the other half of the car varnish No. 2 is put.
Thus you will see it is so placed that, should the car be turned at any
time, both varnishes on each side will have the same exposure and
circumstances to contend with. This I regard as the best method to test
the durability of varnish. And again let me say that it would be wrong for
me to argue that because the varnish which I use gives me the best
results, therefore I would regard it the best for all to use. This would
be wrong, inasmuch as we have a diversity of climates between Maine and
California, and between the extreme northern and southern States. The
varnish which has failed to give me satisfaction may be most suitable for
other parts of the Union.
As to the second part of my subject, "What length of time may a car safely
remain in service before being taken in for revarnishing?" this must be
regulated by the nature of the run and general treatment of the car while
in service. Through cars are frequently continuously on the road, and
little or no opportunity can be had to attend to them while in service.
Such cars should be called in earlier than those which make shorter runs,
and where ample time is allowed at both ends of the journey to be kept in
order. And again, cars which are run nearest the engine cannot make so
large a running record as those less exposed. Some roads, for a variety of
reasons which might be given, can run cars for 14 months with less wear
than others can run 12 months. So that I hold that the master painter on
every road should keep a complete and correct record of his cars, and have
an opportunity to examine these at intervals and report their condition,
in order to have them called in before they are too far gone for
revarnishing. If this system was more frequently adopted, the rolling
stock of our roads would be more attractive, and the companies would be
the gainers.
I cannot lay down a standard rule as to the exact time a car should remain
in service before being called in for revarnishing, but I find as a
general rule with the cars on the Michigan Central Railroad that they
should not exceed 12 months' service, and new cars, or those painted from
the foundation, should not be allowed to run over 10 months the first
year. By thus allowing a shorter period the first year the car will look
better and wear longer by this mode of treatment. Cars treated in this way
can be kept running for six and seven years without repainting.
* * * * *
THE FIXATION OF MAGNETIC PHANTOMS.
When we place a thin sheet of cardboard or glass upon a magnet and scatter
iron filings over it, we observe the iron to take certain positions and
trace certain lines which Faraday has styled lines of magnetic force, or,
more simply, lines of force. The figure, as a whole, which is thus formed
constitutes a magnetic phantom. The forms of the latter vary with that of
the magnet, the relative positions of the magnet and plate, etc.
[Illustration: METHOD OF FIXING MAGNETIC PHANTOMS.]
The whole space submitted to the influence of the magnet constitutes a
_magnetic field_, which is characterized by the presence of these lines of
force, and the study of which is of the most important character as
regards electro-magnetic action and that of induction. In order to study
these phantoms it is convenient to fix them so that they can be preserved,
projected, or photographed. Fig. 1 shows how they may be fixed. To effect
this, we cover the plate with a layer of mucilage of gum arabic, allow the
latter to harden, and then place the plate over the magnet. Next, iron
filings are scattered over the surface by means of a small sieve, and,
when the curves are well developed,[1] the surface is moistened by the aid
of an ordinary vaporizer. The layer of gum arabic thus becomes softened
and holds the iron filings so that the particles cannot change position.
When the gum has hardened again, the magnet is removed, and the phantom is
fixed.
[Footnote 1: The curves are obtained by striking the plate lightly with a
glass rod.]
We thus have a tangible representation of the magnetic field produced by
the magnet in the plane of the glass plate or sheet of paper. The number
of these lines, or their density, is at every point proportional to the
intensity of the field, and the curves that are traced show their
direction. To finish the definition of the field, it remains to determine
the direction of these lines of force. Such direction is, by definition,
and conventionally, that in which the north pole of a small magnetic
needle, free to move in the field, would travel. It results from this
definition that the lines of force issue from the north pole of a magnet
and re-enter the south pole, since the north pole of a magnet repels the
north pole of a needle, and _vice versa._
These considerations relative to the direction and intensity of the
magnetic field are of the highest importance for the physical theory of
magneto-electric machines.
The following is another method of fixing phantoms, as employed by Prof.
Bailie, of the Industrial School of Physics and Chemistry of the City of
Paris. He begins by forming the phantom, in the usual way, upon paper
prepared with ferrocyanide, and exposes it to daylight for a sufficient
length of time. The filings form a screen which is so much the more
perfect in proportion as it is denser, and, after fixation, there is
obtained a negative phantom, that is to say, one in which the parts where
the field is densest have remained white.
The same processes of fixation apply equally well to galvanic phantoms,
that is to say, to the galvanic fields produced by the passage of a
current in a conductor, and which consists of analogous lines of force.
The processes may be employed very efficaciously and with certainty of
success.--_La Nature._
* * * * *
A CHIPPENDALE SIDEBOARD.
[Illustration: A CHIPPENDALE SIDEBOARD.]
Our illustration this week is of a unique and handsome piece of
Chippendale work. The outline is elegant, and the scrollings delicate. The
pedestals are peculiar in their form, the panels being carved in
draperies, etc. In the frieze are two drawers, with grotesque heads
forming the handles. The back is fitted with shaped glass and surmounted
by an eagle. The whole forms a very characteristic piece of work of the
period, having been made about 1760-1770. As our readers are aware, Thomas
Chippendale published his book of designs in 1764, with the object of
promoting good French design in this field of art. This piece of furniture
was sold at auction lately for 85 guineas.--_Building News._
* * * * *
LIQUEFACTION OF THE ELEMENTARY GASES.
By JULES JAMIN, of the Institute of France.
The earlier experiments of MM. Cailletet and Raoul Pictet in the
liquefaction of gases, and the apparatus by means of which they performed
the process, were described in the _Popular Science Monthly_, March and
May, 1878. The experiments have since been continued and improved upon by
MM. Cailletet and Pictet, and others, with more complete results than had
been attained at the time the first reports were published, and with the
elucidation of some novel properties of gases, and the disclosure of
relations, previously not well understood, between the gaseous and the
liquid condition. The experiments of Faraday, in the compression of gases
by the combined agency of pressure and extreme cold, left six gases which
still refused to enter into the liquid state. They were the two elements
of the atmosphere (oxygen and nitrogen), nitric oxide, marsh-gas, carbonic
oxide, and hydrogen. Many new experiments were tried before the principle
that governs the change from the gaseous to the liquid, or from the liquid
to the gaseous form was discovered. Aime sank manometers filled with air
into the sea till the pressure upon them was equal to that of four hundred
atmospheres; Berthelot, by the expansion of mercury in a thermometer tube,
succeeded in exerting a pressure of seven hundred and eighty atmospheres
upon oxygen. Both series of experiments were without result. M. Cailletet,
having fruitlessly subjected air and hydrogen to a pressure of one
thousand atmospheres, came to the conclusion that it was impossible to
liquefy those gases at the ordinary temperature by pressure alone.
Previously it had been thought that the obstacle to condensing gases by
pressure alone lay in the difficulty of obtaining sufficient pressure, or
in that of finding a vessel suitable for manipulation that would be
capable of resisting it. M. Cailletet's thought led to the discovery of
another fundamental property of gases.
The experiments of Despretz and Regnault had shown that the scope of
Mariotte's law (that the volume of gases increases or diminishes inversely
as the pressure upon them) was limited, and that its limits were different
with different substances. Andrews confirmed the observations of these
investigators, and extended them. Compressing carbonic acid at 13° C. (55°
Fahr.), he found that the rate of diminution in volume increased more
rapidly than Mariotte's law demanded, and at a progressive rate. At fifty
atmospheres the gas all at once assumed the liquid form, became very
dense, and fell to the bottom of the vessel, where it remained separated
from its vapor by a clearly defined surface, like that which distinguishes
water in the air. Experimenting in the same way with the gas at a higher
temperature (21° C. or 70° Fahr.), he found that the same result was
produced, but more slowly; and it seemed to be heralded in advance by a
more rapid diminution in volume previous to the beginning of the change,
which continued after the process had been accomplished; as if an
anticipatory preparation for the liquid state were going on previous to
the completion of the change. Performing the experiment again at 32° C.
(90° Fahr.), the anticipatory preparation and the after-continuation of
the contraction were more marked, and, instead of a separate and distinct
liquid, wavy and mobile striæ were perceived on the sides of the vessel as
the only signs of a change of state which had not yet been effected. At
temperatures above 32° C. (90° Fahr.), there were neither striæ nor
liquefaction, but there seemed to be a suggestion of them, for, under a
particular degree of pressure, the density of the gas was augmented, and
its volume diminished at an increasing rate. The temperature of 32° C.
(90° Fahr.) is, then, a limit, marking a division between the temperatures
which permit and those which prevent liquefaction; it is the critical
point, at which is defined the separation, for carbonic acid, between two
very distinct states of matter. Below this point, the particular matter
may assume the aspect of a liquid; above it, the gas cannot change its
appearance, but enters into the opposite constitution from that of a
liquid.
Generally, a liquid has considerably greater density than its vapor. But,
if a vessel containing both is heated, the liquid experiences a dilatation
which is gradually augmented till it equals and even exceeds that of the
gas; whence, of course, an equal volume of the liquid will weigh less and
less. On the other hand, a constantly larger quantity of vapor is formed,
which accumulates above the liquid and becomes heavier and heavier. Now if
the density of the vapor increases, and that of the liquid diminishes,
they will reach a point, under a suitable temperature, when they will be
the same. There will then be no reason for the liquid to sink or the vapor
to rise, or for the existence of any line of separation between them, and
they will be mixed and confounded. They will no longer be distinguishable
by their heat of constitution. It is true that, in passing into the state
of a vapor, a liquid absorbs a great deal of latent heat, but that is
employed in scattering the molecules and keeping them at a distance; and
there will be none of it if the distance does not increase. We are then,
at this stage of our experiments, in the presence of a critical point, at
which we do not know whether the matter is liquid or gaseous; for, in
either condition, it has the same density, the same heat of constitution,
and the same properties. It is a new state, the gaso-liquid state. An
experiment of Cagniard-Latour re-enforced this explanation of the
phenomena. Heating ether in closed vessels to high temperatures, he
brought it to a point where the liquid could be made wholly to disappear,
or to be suddenly reformed on the slightest elevation or the slightest
depression of temperature accordingly as it was raised just above or
cooled to just below the critical point. The discovery of these properties
suggested an explanation of the failure of previous attempts to liquefy
air. Air at ordinary low temperatures is in the gaso-liquid condition, and
its liquefaction is not possible except when a difference exists between
the density of the vapor and that of the liquid greater than it is
possible to produce under any conditions that can exist then. It was
necessary to reduce the temperature to below the critical point; and it
was by adopting this course that MM. Cailletet and Raoul Pictet achieved
their success. The rapid escape of the compressed gas itself from a
condition of great condensation at an extremely low temperature was
employed as the agent for producing a greater degree of cold than it had
been possible before to obtain. M. Cailletet used oxygen escaping at -29°
C. from a pressure of three hundred atmospheres; M. Raoul Pictet, the same
gas escaping at -140° from a pressure of three hundred and twenty
atmospheres; and both obtained oxygen and nitrogen, and M. Pictet
hydrogen, in what they thought was a liquid, and possibly even in a solid
form.
Still, it could not be asserted that hydrogen and the elements of the air
had been completely liquefied. These gases had not yet been seen collected
in the static condition at the bottom of a tube and separated from their
vapors by the clearly defined concave surface which is called a
_meniscus._ The experiments had, however, proved that liquefaction is
possible at a temperature of below -120° C. (-184° Fahr.). To make the
process practicable, it was only necessary to find sufficiently powerful
refrigerants; and these were looked for among gases that had proved more
refractory than carbonic acid and protoxide of nitrogen. M. Cailletet
selected ethylene, a hydrocarbon of the same composition as illuminating
gas, which, when liquefied by the aid of carbonic acid and a pressure of
thirty-six atmospheres, boils at -103° C. (-153° Fahr.). M. Wroblewski, of
Cracow, who had witnessed some of M. Cailletet's experiments, and obtained
his apparatus, and M. Olzewski, in association with him, also experimented
with ethylene, and had the pleasure of recording their first complete
success early in April, 1883. Causing liquid ethylene to boil in an
air-pump vacuum at -103° C., they were able to produce a temperature of
-150° C. (-238° Fahr.), the lowest that had ever been observed. Oxygen,
having been previously compressed in a glass tube, became a permanent
liquid, with a clearly defined meniscus. It presented itself, like the
other liquefied gases, under the form of a transparent and colorless
substance, resembling water, but a little less dense. Its critical point
was marked at -113° C. (-171° Fahr.), below which the liquid could be
formed, but never above it; while it boiled rapidly at -186° C. (-303°
Fahr.). A few days afterward, the Polish professors obtained the
liquefaction of nitrogen, a more refractory gas, under a pressure of
thirty-six atmospheres, at -146° C. (-231° Fahr.). Long, difficult, and
expensive operations were required to produce this result, for the extreme
degree of cold it demanded had to be produced by boiling large quantities
of ethylene in a vacuum. M. Cailletet devised a cheaper process, by
employing another hydrocarbon that rises from the mud of marshes, and is
called _formene_. It is less easily liquefied than ethylene, but for that
very reason can be boiled in the air at a lower temperature, or at -160°C.
(-256° Fahr.); and at this temperature nitrogen and oxygen can be
liquefied in a bath of formene as readily as sulphurous acid in the common
freezing mixture.
MM. Cailletet, Wroblewski, and Olzewski have continued their experiments
in liquefaction, and acquired increased facility in the handling of liquid
ethylene, formene, atmospheric air, oxygen, and nitrogen. M. Olzewski was
able to report to the French Academy of Sciences, on the 21st of July,
1884, that by placing liquefied nitrogen in a vacuum he had succeeded in
producing a temperature of -213°C. (-351° Fahr.), under which hydrogen was
liquefied. Contrary to the suppositions founded on the metallic behavior
of this element, that it would present the appearance of a molten metal,
like mercury, the liquid had the mobile behavior and the transparency of
the hydrocarbons.
* * * * *
EXAMINATION OF FATS.
The methods employed up to the present in examination of fats, animal and
vegetable, are mere reactions lacking general application; scattered
throughout the literature, and doubtful with regard to reliability, they
are of little or no value to the experimenter--an approximate quantitative
examination even of a simple mixture being exceedingly difficult if not
impossible, since the qualitative composition of fatty substances is the
same, and the separation of the nearer components impracticable. The
object of analysis consisted in estimating the accompanying impurities of
fat, as, resin, albuminoids, and pigments. The nature of these substances
depends on the mode of extraction and preservation of the fat, and are
subject in the course of time to alteration. The only reaction based upon
the chemical constitution of fat is produced by treatment of oleic or
linoleic acid with nitrous acid, which therefore is of some value in the
examination of drying oils. Of general application are the methods which
correspond to the chemical constitution of fats, and thus determine the
relative quantity of the components; advantage can then be derived from
qualitative reactions, inasmuch as they further affirm the result of the
quantitative test, or dispel any doubt with regard to the correctness of
the result. The principal methods which comply with these demands have
been carefully studied by Hueble for the purpose of discovering a process
of general application; methods founded on the determination of density,
freezing, and melting point were compared with those dependent on the
solubility of fatty substances in glacial acetic acid or a mixture of
alcohol and acetic acid; also the method of Hehner for testing of butter,
the determination of glycerine and oleic acid, and at length the process
of saponification. Nearly all fats contain members belonging to one of the
three series of fatty acids, _e.g._, acids of the type of acetic acid
(stearic and palmitic acids); such as are derivatives of acrylic acid
(oleic and erucic acids); and such as are homologues of tetrolic acid
(linoleic acid). It is likely that the relative quantity of each of these
acids is variable, with regard to the same fat, within definite limits,
and changes with the nature of the fatty substance. The groups of fatty
acids are distinguished by a characteristic deportment toward halogens;
while members of the first series are indifferent to haloids, those of the
second and third class combine readily, without suffering substitution,
with two respectively four atoms of a haloid. In view of this behavior the
first series is termed saturated, the second and third that of unsaturated
acids. Addition of halogen to one of the unsaturated acids yields on
subsequent examination an invariable quantity of the former, representing
two or four atoms, according to one or the other of unsaturated groups;
and as the molecular weights of fatty acids are unequal, the percentage
quantity of halogen will be found varying with regard to members belonging
to the same series. The amount of iodine absorbed by some of the fatty
acids is illustrated by the following items:
Hypogallic acid, C_{16}H_{30}O_{2}, combines with 100.00 grammes. iodine.
Oleic acid, C_{18}H_{34}O_{2} " " 90.07 " "
Erucic acid, C_{22}H_{42}O_{2} " " 75.15 " "
Ricinoleic acid, C_{18}H_{34}O_{3} " " 85.24 " "
Linoleic acid, C_{16}H_{28}O_{2} " " 201.59 " "
Of the halogens employed in the examination, iodine is preferable to
either chlorine or bromine; it acts but slowly at ordinary, but
energetically at elevated temperatures. The reagents are solution of
mercury iodo-chloride prepared by dissolving of 25 grms. iodine, 500 c.c.
alcohol of 95 per cent., and of 30 grms. mercury chloride in an equal
measure of the same solvent; both liquids are filtered and united; a
standard solution of sodium hyposulphite produced by digestion of 24 grms.
of the dry salt with 1 liter water and titration with iodine solution;
solution of potassium iodide of 1:10; chloroform, and finally a solution
of starch. The above solution of mercury iodo-chloride acts on both free
unsaturated acids and glycerides, producing addition products. For testing
a sample of 0.2 to 0.4 grm. of a liquid, and from 0.8 to 1.0 grm. of a
solid fat being used, which is dissolved in 10 c.c. chloroform and treated
with 20 c.c. mercury iodo-chloride solution run into it from a burette, if
the liquid appear opalescent a further measure of chloroform is
introduced, while the amount of mercury iodo-chloride must be such as to
produce a brownish coloration of the chloroform for two subsequent hours.
The excess of iodine is determined, on addition of from 10 to 15 c.c.
potassium iodide solution and 150 c.c. distilled water, by means of
caustic soda. From a burette divided into 0.1 c.c. a solution of caustic
soda is poured with continual gyration of the flask into the tinged
liquid, and the percentage of combined iodine ascertained by difference;
for this purpose 20 c.c. of mercury iodo-chloride are tested, on
introduction of a solution of potassium iodide and starch, previously to
its use as reagent. Adulteration of solid or semi-liquid fats, especially
lard, butter, and tallow, with vegetable oils are readily detected by this
method, since the latter yield on examination a high percentage of iodine.
Animal fats, absorb comparatively less halogen than vegetable fats, and
the power to combine with iodine increases with the transition from the
solid to the liquid state, and attains its maximum with vegetable
oils--the method being adapted to the examination of fat mixtures
containing glycerides and free saturated fatty acids, provided that
substances which under similar conditions combine with iodine are absent.
These conditions are fulfilled with regard to the examination of animal
fats and soap. Ethereal oils are also acted upon by iodine; the reaction
proceeds similar to that observed in ordinary fat mixtures. Alcoholic
mercury iodo-chloride can probably be used with success in synthetical
chemistry, as it allows determination of the free affinities of the
molecule and conversion of unsaturated compounds into saturated
chlorine-iodo addition products.--_Rundschau._
* * * * *
NOTES ON NITRIFICATION.[2]
[Footnote 2: A paper by R. Warington, read before the Chemical Section of
the British Association at Montreal.]
By R. WARINGTON.
In the following brief notes I propose to consider in the first place the
present position of the theory of nitrification, and next to give a short
account of the results of some recent experiments conducted in the
Rothamsted Laboratory.
_The Theory of Nitrification._--The production of nitrates in soils, and
in waters contaminated with sewage, are facts thoroughly familiar to
chemists. It is also well known that ammonia, and various nitrogenous
organic matters, are the materials from which the nitric acid is produced.
Till the commencement of 1877 it was generally supposed that this
formation of nitrates from ammonia or nitrogenous organic matter was the
result of simple oxidation by the atmosphere. In the case of soil it was
imagined that the action of the atmosphere was intensified by the
condensation of oxygen in the pores of the soil; in the case of waters no
such assumption was possible. This theory was most unsatisfactory, as
neither solutions of pure ammonia, nor of any of its salts, could be
nitrified in the laboratory by simple exposure to air. The assumed
condensation of oxygen in the pores of the soil also proved to be a
fiction as soon as it was put by Schloesing to the test of experiment.
Early in 1877, two French chemists, Messrs. Schloesing and Müntz,
published preliminary experiments showing that nitrification in sewage and
in soils is the result of the action of an organized ferment, which occurs
abundantly in soils and in most impure waters. This entirely new view of
the process of nitrification has been amply confirmed both by the later
experiments of Schloesing and Müntz, and by the investigations of other
chemists, among which are those by myself conducted in the Rothamsted
Laboratory.
The evidence for the ferment theory of nitrification is now very complete.
Nitrification in soils and waters is found to be strictly limited to the
range of temperature within which the vital activity of living ferments is
confined. Thus nitrification proceeds with extreme slowness near the
freezing-point, and increases in activity with a rise in temperature till
37° is reached; the action then diminishes, and ceases altogether at 55°.
Nitrification is also dependent on the presence of plant-food suitable for
organisms of low character. Recent experiments at Rothamsted show that in
the absence of phosphates no nitrification will occur. Further proof of
the ferment theory is afforded by the fact that antiseptics are fatal to
nitrification. In the presence of a small quantity of chloroform, carbon
bisulphide, salicylic acid, and apparently also phenol, nitrification
entirely ceases. The action of heat is equally confirmatory. Raising
sewage to the boiling-point entirely prevents its undergoing
nitrification. The heating of soil to the same temperature effectually
destroys its nitrifying power. Finally, nitrification can be started in
boiled sewage, or in other sterilized liquid of suitable composition, by
the addition of a few particles of fresh surface soil or a few drops of a
solution which has already nitrified; though without such addition these
liquids may be freely exposed to filtered air without nitrification taking
place.
The nitrifying organism has been submitted as yet to but little
microscopical study; it is apparently a micrococcus.
It is difficult to conceive how the evidence for the ferment theory of
nitrification could be further strengthened; it is apparently complete in
every part. Although, however, nearly the whole of this evidence has been
before the scientific public for more than seven years, the ferment theory
of nitrification can hardly be said to have obtained any general
acceptance; it has not indeed been seriously controverted, but neither has
it been embraced. In hardly a single manual of chemistry is the production
of saltpeter attributed to the action of a living ferment existing in the
soil. Still more striking is the absence of any recognition of the
evidence just mentioned when we turn to the literature and to the public
discussions on the subjects of sewage, the pollution of river water, and
other sanitary questions. The oxidation of the nitrogenous organic matter
of river water is still spoken of by some as determined by mere contact
with atmospheric oxygen, and the agitation of the water with air as a
certain means of effecting oxidation; while by others the oxidation of
nitrogenous organic matter in a river is denied, simply because free
contact with air is not alone sufficient to produce oxidation. How much
light would immediately be thrown on such questions if it were recognized
that the oxidation of organic matter in our rivers is determined solely by
the agency of life, is strictly limited to those conditions within which
life is possible, and is most active in those circumstances in which life
is most vigorous. It is surely most important that scientific men should
make up their minds as to the real nature of those processes of oxidation
of which nitrification is an example. If the ferment theory be doubted,
let further experiments be made to test it, but let chemists no longer go
on ignoring the weighty evidence which has been laid before them. It is
partly with the view of calling the attention of English and American
chemists to the importance of a decision on this question that I have been
induced to bring this subject before them on the present occasion. I need
hardly add that such results as the nitrification of sewage by passing it
through sand, or the nitrification of dilute solutions of blood prepared
without special precaution, are no evidence whatever against the ferment
theory of nitrification. If it is to be shown that nitrification will
occur in the absence of any ferment, it is clear that all ferments must be
rigidly excluded during the experiments; the solutions must be sterilized
by heat, the apparatus purified in a similar manner, and all subsequent
access of organisms carefully guarded against. It is only experiments made
in this way that can have any weight in deciding the question.
Leaving now the theory of nitrification, I will proceed to say a few
words, first, as to the distribution of the nitrifying organism in the
soil; secondly, as to the substances which are susceptible of
nitrification; thirdly, upon certain conditions having great influence on
the process.
_The Distribution of the Nitrifying Organism in the Soil._--Three series
of experiments have been made on the distribution of the nitrifying
organism in the clay soil and subsoil at Rothamsted. Advantage was taken
of the fact that deep pits had been dug in one of the experimental fields
for the purpose of obtaining samples of the soil and subsoil. Small
quantities of soil were taken from freshly-cut surfaces on the sides of
these pits at depths varying from 2 inches to 8 feet. The soil removed was
at once transferred to a sterilized solution of diluted urine, which was
afterward examined from time to time to ascertain if nitrification took
place. These experiments are hardly yet completed; the two earlier series
of solutions have, however, been examined for eight and seven months
respectively. In both these series the soil taken from 2 inches, 9 inches,
and 18 inches from the surface has been proved to contain the nitrifying
organism by the fact that it has produced nitrification in the solutions
to which it was added; while in twelve distinct experiments made with soil
from greater depths no nitrification has yet occurred, and we must
therefore conclude that the nitrifying organism was not present in the
samples of soil taken. The third series of experiments has continued as
yet but three months and a half; at present no nitrification has occurred
with soil taken below 9 inches from the surface. It would appear,
therefore, that in a clay soil the nitrifying organism is confined to
about 18 inches from the surface; it is most abundant in the first 6
inches. It is quite possible, however, that in the channels caused by
worms, or by the roots of plants, the organism may occur at greater
depths. In a sandy soil we should expect to find the organism at a lower
level than in clay, but of this we have as yet no evidence. The facts here
mentioned are in accordance with the microscopical observations made by
Koch, who states that the micro-organisms in the soils he has investigated
diminish rapidly in number with an increasing depth; and that at a depth
of scarcely 1 meter the soil is almost entirely free from bacteria.
Some very practical conclusions may be drawn from the facts now stated. It
appears that the oxidation of nitrogenous matter in soil will be confined
to matter near the surface. The nitrates found in the subsoil and in
subsoil drainage waters have really been produced in the upper layer of
the soil, and have been carried down by diffusion, or by a descending
column of water. Again, in arranging a filter bed for the oxidation of
sewage, it is obvious that, with a heavy soil lying in its natural state
of consolidation, very little will be gained by making the filter bed of
considerable depth; while, if an artificial bed is to be constructed, it
is clearly the top soil, rich in oxidizing organisms, which should be
exclusively employed.
_The Substances Susceptible of Nitrification._--The analyses of soils and
drainage waters have taught us that the nitrogenous humic matter resulting
from the decay of plants is nitrifiable; also that the various nitrogenous
manures applied to land, as farmyard manure, bones, fish, blood, rape
cake, and ammonium salts, undergo nitrification in the soil. Illustrations
of many of these facts from the results obtained in the experimental
fields at Rothamsted have been published by Sir J.B. Lawes, Dr. J.H.
Gilbert, and myself, in a recent volume of the _Journal_ of the Royal
Agricultural Society of England. In the Rothamsted Laboratory, experiments
have also been made on the nitrification of solutions of various
substances. Besides solutions containing ammonium salts and urea, I have
succeeded in nitrifying solutions of asparagine, milk, and rape cake.
Thus, besides ammonia, two amides, and two forms of albuminoids have been
found susceptible of nitrification. In all cases in which amides or
albuminoids were employed, the formation of ammonia preceded the
production of nitric acid. Mr. C.F.A. Tuxen has already published in the
present year two series of experiments on the formation of ammonia and
nitric acids in soils to which bone-meal, fish-guano, or stable manure had
been applied; in all cases he found the formation of ammonia preceded the
formation of nitric acid.
As ammonia is so readily nitrifiable, we may safely assert that every
nitrogenous substance which yields ammonia when acted upon by the
organisms present in soil is also nitriflable.
_Certain Conditions having Great Influence in the Process of
Nitrification._--If we suppose that a solution containing a nitrifiable
substance is supplied with the nitrifying organism, and with the various
food constituents necessary for its growth and activity, the rapidity of
nitrification will depend on a variety of circumstances:
1. The degree of concentration of the solution is important. Nitrification
always commences first in the weakest solution, and there is probably in
the case of every solution a limit of concentration beyond which
nitrification is impossible.
2. The temperature has great influence. Nitrification proceeds far more
rapidly in summer than winter.
3. The presence or absence of light is important. Nitrification is most
rapid in darkness; and in the case of solutions, exposure to strong light
may cause nitrification to cease altogether.
4. The presence of oxygen is of course essential. A thin layer of solution
will nitrify sooner than a deep layer, owing to the larger proportion of
oxygen available. The influence of depth of fluid is most conspicuous in
the case of strong solutions.
5. The quantity of nitrifying organism present has also a marked effect. A
solution seeded with a very small amount of organism will for a long time
exhibit no nitrification, the organism being (unlike some other bacteria)
of very slow growth. A solution receiving an abundant supply of the
ferment will exhibit speedy nitrification, and strong solutions may by
this means be successfully nitrified, which with small seedings would
prove very refractory. The speedy nitrification which occurs in soil (far
more speedy than in experiments in solutions under any conditions yet
tried) is probably owing to the great mass of nitrifying organisms which
soil contains, and to the thinness of the liquid layer which covers the
soil particles.
6. The rapidity of nitrification also depends on the degree of alkalinity
of the solution. Nitrification will not take place in an acid solution; it
is essential that some base should be present with which the nitric acid
may combine; when all available base is used up, nitrification ceases.
It appeared of interest to ascertain to what extent nitrification would
proceed in a dilute solution of urine without the addition of any
substance save the nitrifying ferment. As urea is converted into ammonium
carbonate in the first stage of the action of the ferment, a supply of
salifiable base would at first be present, but would gradually be
consumed. The result of the experiment showed that only one-half the
quantity of nitric acid was formed in the simple urine solution as in
similar solutions containing calcium and sodium carbonate. The
nitrification of the urine had evidently proceeded until the whole of the
ammonium had been changed into ammonium nitrate, and the action had then
ceased. This fact is of practical importance. Sewage will be thoroughly
nitrified only when a sufficient supply of calcium carbonate, or some
other base, is available. If, instead of calcium carbonate, a soluble
alkaline salt is present, the quantity must be small, or nitrification
will be seriously hindered.
Sodium carbonate begins to have a retarding influence on the commencement
of nitrification when its amount exceeds 300 milligrammes per liter, and
up to the present time I have been unable to produce an effective
nitrification in solutions containing 1.000 gramme per liter.
Sodium hydrogen carbonate hinders far less the commencement of
nitrification.
Ammonium carbonate, when above a certain amount, also prevents the
commencement of nitrification. The strongest solution in which
nitrification has at present commenced contained ammonium carbonate
equivalent to 368 milligrammes of nitrogen per liter. This hinderance of
nitrification by the presence of an excess of ammonium carbonate
effectually prevents the nitrification of strong solutions of urine, in
which, as already mentioned, ammonium carbonate is the first product of
fermentation.
Far stronger solutions of ammonium chloride can be nitrified than of
ammonium carbonate, if the solution of the former salt is supplied with
calcium carbonate. Nitrification has in fact commenced in chloride of
ammonium solutions containing more than two grammes of nitrogen per liter.
The details of the recent experiments, some of the results of which we
have now described, will, it is hoped, shortly appear in the _Journal_ of
the Chemical Society of London.
Harpenden, July 21.
* * * * *
ANILINE DYES IN DRESS MATERIALS.
By Professor CHARLES O'NEILL.
Twenty-eight years ago Mr. Perkin discovered the first of the aniline
dyes. It was the shade of purple called mauve, and the chief agent in its
production was bichromate of potash. This salt is not actively poisonous,
and no one thought of attributing injurious properties to materials dyed
with the aniline mauve. Next in chronological order came magenta red. It
was first made from aniline by the agency of mercurial salts, and
afterward by that form of arsenic known to chemists as arsenic acid. The
fact that this at one time fashionable color was prepared by means of an
arsenical compound was spread through the country in a very impressive
manner by the great trial as to whether the patent was valid or not, all
turning upon the expression in the specification of "dry arsenic acid,"
and the disputes of scientists whether this expression meant arsenic acid
with or without water. The public mind had been for some time previously
exercised and alarmed by accounts of sickness and debility caused by
arsenical paper-hangings; it was, therefore, easy for pseudo scientists to
create an opinion that the magenta dye must be also poisonous, and that
persons wearing materials dyed with this color were liable to absorb
arsenic and suffer from its action. Ever since there have been, at
intervals, statements more or less circumstantial, that individuals have
suffered from wearing materials dyed with some of the artificial dyes. At
the present time these statements are emphasized by the exhibition at the
Healtheries of models of skin diseases said to be actually produced by the
wearing of dyed garments. Whether it be true or not that any form of skin
disease has been produced by the wearing of dyed articles of clothing is
simply a question of evidence, and there is evidence enough to show that
individuals have experienced ill effects who have worn clothing dyed with
artificial colors. But, as far as we know, there is an entire want of any
evidence that will satisfactorily show that the inconvenience suffered by
wearers of these dyed goods has been owing to the dyeing material. Years
must elapse before chemists or physicians can hope to become thoroughly
informed of the physiological action produced by the cutaneous absorption
of the thousands of new products which the ingenuity and industry of
technological chemists have made available for the manufacture of colors;
they are also new to science, most of them very complex in their
constitution, and so dissimilar to previously studied compounds used by
the dyer, that it may be said we have nearly everything to learn
concerning their action upon the human economy. With respect to dyed
woolen and silk goods it is almost entirely a question as to the innocence
or otherwise of the coloring matter itself, which in nine cases out of ten
is an organic body containing no mineral matter of any sort, and not
requiring the assistance of any mordant to enable it to dye.
Considerations of arsenic, or antimony, or mercury existing in the dyed
stuffs are absolutely excluded. In a few cases the dyestuff is a zinc
compound, and zinc in small traces may possibly be fixed by the material,
but this metal is not known to be actively noxious. Textiles made from
fibers of animal origin do not require, and as a rule do not tolerate, the
addition of any metal in dyeing with the artificial colors, and if the
manufacture of the color require the use of a metal, such as arsenic,
which by unskillfulness or carelessness is left in it when delivered to
the dyer, the tendency of the animal fiber is to reject it.
But the case with regard to textiles made from vegetables fibers is quite
different; upon materials made from cotton, flax, jute, or other fiber of
the vegetable kingdom, the new aniline colors cannot be fixed without the
assistance of other bodies acting the part of mordants. Some of these
bodies are actively poisonous in their nature, and introduce a possible
element of danger to the wearer of the dyed article. For many years,
almost the only method of dyeing cotton goods with the aniline colors
consisted in a preliminary steeping in sumac or tannic acid, followed by a
passage in some suitable compound of tin, and subsequent dyeing in the
coloring matter. Sumac and tin have been used for two hundred years or
more as the dyer's basis for a considerable number of shades of color from
old dye-stuffs; there never has been the least suspicion that there was
anything hurtful in colors so dyed. Sumac or tannic acid, in combination
with alumina, may be held to be equally inoffensive; now it is a fact that
the great bulk of cotton goods are dyed with the aniline colors by the
agency of these harmless chemicals. But of late years the dyers of certain
goods, and the calico printers generally, have found an advantage in the
use of tartar emetic, and other compounds of antimony, to fix aniline
colors; besides this, some colors are fixed in calico printing by means of
an arsenical alumina mordant; it need not be mentioned that antimony, as
well as arsenic, is, when administered internally, an active poison in
even small quantities, and that externally both are injurious under
certain conditions. An alarmist would require nothing further than this
statement to feel himself justified in attributing everything bad to
fabrics so colored; but the practical dyer or calico printer knows that
though he employs these poisonous bodies in his business, and that some
portion of them does actually accompany the dyed material in its finished
state, not only is the quantity excessively small, but that it is in such
a state of combination as to be completely inert and innoxious. In the
case of tartar emetic, it is the tannate of antimony which remains upon
the cloth, a compound of considerable stability, and almost perfectly
insoluble in water; in the case of a few colors fixed by the arsenical
alumina mordant, the arsenic is in an insoluble state of combination with
the alumina, in fact, the poisons are in the presence of their antidotes,
and not even the most scrupulous manufacturer has any fear that he is
turning out goods which can be hurtful to the wearer. Persons quite
unacquainted with the process of dyeing are apt to think that goods are
dyed by simply immersing them in a colored liquid and then drying them
with all the color on them and all that the color contains; they do not
know that in all usual cases of dyeing a careful washing in a plentiful
supply of water is the final process in the dye-house, and that nothing
remains upon the cloth which can be washed out by water, the color being
retained by a sort of attraction or affinity between it and the fiber, or
mordant on the fiber. Dyeing is not like painting or even the printing or
staining of paper for hangings, where the vehicle and color in its
entirety is applied and remains. It follows, therefore, that many
chemicals used in dyeing have only a transitory use, and are washed away
completely--such as oil of vitriol, much used in woolen dyeing--and that
of others only a very minute quantity is finally left on the cloth, as is
the case in antimony and arsenic in cotton dyeing and printing.
There is evidently among working dyers, as among all other classes, an
unknown amount of carelessness, ignorance, and stupidity, from which
employers are constantly suffering in the shape of spoiled colors and
rotted cloth. It is not for us to say that the public may not at times
have to suffer also from neglect of the most common treatments which
should remove injurious matters from dyed goods; what can be said is, that
if the dyeing processes for aniline colors be followed out with ordinary
care and intelligence, it is extremely improbable that anything left in
the material should be injurious to human health.--_Manchester Textile
Recorder._
* * * * *
CASE OF RESUSCITATION AND RECOVERY AFTER APPARENT DEATH BY HANGING.
By ERNEST W. WHITE, M.B. Lond., M.R.C.P., Senior Assistant Medical Officer
to the Kent Lunatic Asylum; Associate, Late Scholar, of King's College,
London.
The following case, from its hopelessness at the outset, yet ultimate
recovery under the duly recognized forms of treatment, is of such interest
as to demand publicity, and will afford encouragement to others in moments
of doubt.
M.A. S----, aged fifty-three, was admitted into the Kent Lunatic Asylum at
Chartham on Oct. 3, 1882, suffering from melancholia, the duration of
which was stated to have been three months. She had several times
attempted suicide by drowning and strangulation. She was on admission
ordered a mixture containing morphia and ether thrice daily, to allay her
distress. On Oct. 10 she attempted suicide by tying a stocking, which she
had secreted about her person, round her neck. Shortly afterward, with
similar intent, she threw herself downstairs. On Jan. 4, 1883, she
attempted to strangle herself with her apron. On the 30th of November
following, at 4 P.M. she evaded the attendants, and made her way to the
bath-room of of No. 1 ward, the door of which had been left unfastened by
an attendant. She then suspended herself from a ladder there by means of
portions of her dress and underclothing tied together. A patient of No. 1
ward discovered her suspended from the ladder eight minutes after she had
last seen her in the adjoining watercloset, and gave the alarm.
The woman was quickly cut down, and the medical officers summoned. In the
interval cold affusion was resorted to by the attendant in charge, but the
patient was to all appearances dead. The junior assistant medical officer,
Mr. J. Reynolds Salter, M.B. Lond., arrived after about three minutes, and
at once resorted to artificial respiration by the Silvester method. A
minute or so later the medical superintendent and myself joined him. At
this time the condition of the patient was as follows: The face presented
the appearance known as facies hippocratica: the eyeballs were prominent,
the corneæ glassy, the pupils widely dilated, not acting to light, and
there was no reflex action of the conjunctivæ; the lips were livid, the
tongue tumefied, but pallid, the skin ashy pale, the cutaneous tissues
apparently devoid of elasticity. There was an oblique depressed mark on
the neck, more evident on the left side; the small veins and capillaries
of the surface of the body were turgid with coagulating blood the surface
temperature was extremely low. She was pulseless at the wrists and
temples. There was no definite beat of the heart recognizable by the
stethoscope.
There was absolute cessation of all natural respiratory efforts, complete
unconsciousness, total abolition of reflex action and motion, and
galvanism with the ordinary magneto-electric machine failed to induce
muscular contractions. The urine and fæces had been passed involuntarily
during or immediately subsequent to the act of suspension. As the
stethoscope revealed that but a small amount of air entered the lungs with
each artificial inspiration, the tongue was at once drawn well forward,
and retained in that position by an assistant, with the result that air
then penetrated to the smaller bronchi. Inspiration and expiration were
artificially imitated about ten times to the minute. In performing
expiration the chest was thoroughly compressed. The lower extremities were
raised, and manual centripetal frictions freely applied. In the intervals
of these applications warmth to the extremities was resorted to.
About ten minutes from the commencement of artificial respiration we
noticed a single weak spasmodic contraction of the diaphragm, the feeblest
possible effort at natural respiration. Simultaneously, very distant weak
reduplicated cardiac pulsations, numbering about 150 to the minute, became
evident to the stethoscope. The reduplication implied that the two sides
of the heart were not acting synchronously, owing to obstruction to the
pulmonary circulation induced by the asphyxiated state. Artificial
respiration was steadily maintained, and during the next half hour
spasmodic contractions of the diaphragm occurred at gradually diminishing
intervals, from once in three minutes to three or four times a minute.
These natural efforts were artificially aided as far as possible. At 5:45
P.M. natural respiration was fairly though insufficiently established, the
skin began to lose its deadly hue, and titillation of the fauces caused
weak reflex contractions. Flagellation with wet towels was now freely
resorted to, and immediately the natural efforts at respiration were
increased to twice their previous number. The administration of a little
brandy and water by the mouth failed, as the liquid entered the larynx.
Ammonia was applied to the nostrils, and the surface temperature was
increased by warm applications and clothing. At 6 P.M. artificial
respiration was no longer necessary. The heart sounds then numbered 140 to
the minute, the right and left heart still acting separately. A very small
radial pulse could also be felt. At 6:45 P.M. the woman was put to bed,
warmth of surface maintained, and hot coffee and beef-tea given in small
quantities.
Great restlessness and jactitation set in with the renewal of the
circulation in the extremities. An enema of two ounces of strong beef-tea
was administered at 10 P.M. The amount of organic effluvium thrown off by
the lungs on the re-establishment of respiration was very great and
tainted the atmosphere of the room and adjoining ward. The pupils,
previously widely dilated, began to contract to light at 11 P.M. Imperfect
consciousness returned at 5 P.M. the following day (Dec. 1), and about an
hour later she vomited the contents of the stomach (bread, etc., taken on
Nov. 30). Small quantities of beef-tea were given by the mouth during the
night. At 9 A.M. air entered the lungs freely, and there were no symptoms
of pulmonary engorgement beyond slight basic hypostasis; the pulse
remained at 140, and the heart sounds reduplicated; she was semiconscious,
very drowsy, in a state of mental torpor, with confused ideas when roused,
and she complained of rheumatic-like pains all over her.
The temperature was 100.2°; the facial expression more natural; the tongue
remained somewhat swollen and sore; she was no longer restless; she took
tea, beef-tea, milk, etc., well; the functions of the secreting organs
were being restored; she perspired freely; had micturated; the mucous
membrane of the mouth was moist, and there was a tendency to tears without
corresponding mental depression. The patient was ordered a mixture of
ether and digitalis every four hours. On December 2 the pulse was 136, and
the heart sounds reduplicated. The following day she was given bromide of
potassium in place of the ether in the digitalis mixture. On the 4th the
pulse was 126; reduplication gone. On the 6th the pulse was 82, and the
temperature fell with the pulse rate. She was well enough to get into the
ward for a few hours. Her memory, especially for recent events, was at
that time greatly impaired. On the 12th she still complained of muscular
pains like those of rheumatism. Apart from that, she was enjoying good
bodily health.
A curious fact in connection with this case is that since this attempt at
suicide she has steadily improved mentally, has lost her delusions, is
cheerful, and employs herself usefully with her needle. She converses
rationally, and tells me she recollects the impulse by which she was led
to hang herself, and remembers the act of suspension; but from that time
her memory is a blank, until two days subsequently, when her husband came
to see her, and when she expressed great grief at having been guilty of
such a deed. Her bodily health is now (June 30, 1884) more robust than
formerly, and she is on the road to mental convalescence.
_Remarks._--The successful issue of this case leads me to draw the
following inferences: 1. That in cases of suspended animation similar to
the above there is no symptom by which apparent can be distinguished from
real death. 2. That in artificial respiration alone do we possess the
means of restoring animation when life is apparently extinct from
asphyxia, and that, with the tongue drawn well forward and retained there
by the hand or an elastic band, the Silvester method is complete and
effective. 3. That artificial respiration may be necessary for two hours
or more before the restoration of adequate natural efforts, and that the
performance of the movements ten times to the minute is amply sufficient,
and produces a better result than a more rapid rate. 4. That galvanism,
ammonia to the nostrils, cold affusion, and stimulants by the mouth are
practically useless in the early stage. 5. That on the re-establishment of
the reflex function we possess a powerful auxiliary agent in flagellation
with wet towels, etc. 6. That centripetal surface frictions and the
restoration of the body temperature by warm applications aid recovery. 7.
That the heart, if free from organic disease, has great power of
overcoming the distention of its right cavities and the obstruction to the
pulmonary circulation, although its action may for a time be seriously
deranged, as evidenced by reduplication of its sounds. 8. That when the
heart's action remains excessively feeble, and the right and left heart
fail to contract synchronously, it would be justifiable to open the
external jugular vein. 9. That during recovery the lungs are heavily taxed
in purifying the vitiated blood, as shown by the excessive amount of
organic impurities exhaled. 10. That restlessness and jactitation
accompany the restoration of nerve function, and that vomiting occurs with
returning consciousness. 11. That pains like those of rheumatism are
complained of for some days subsequently, these probably resulting from
the sudden arrest of nutrition in the muscles.
Chartham, near Canterbury.
--_Lancet._
* * * * *
THE INVENTORS' INSTITUTE.
The twenty-second session of the Inventors' Institute was opened on
October 27, the chair being taken by Vice-Admiral J.H. Selwyn, one of the
vice-presidents, at the rooms of the institute, Lonsdale Chambers, 27
Chancery Lane, London. The chairman, in delivering the inaugural address,
said that in the absence of their president, the Duke of Manchester, it
became his duty to open the session of 1885. The institute having been
established in 1862, this was their twenty-second anniversary. At the time
of its establishment a greater number of members were rapidly enrolled
than they could now reckon, although a large number had joined since the
commencement of the present year. In 1862 a considerable amount of
enthusiasm on the part of inventors had arisen, from the fact that at that
time the leading journals had advocated the views of certain manufacturers
as to sweeping away the patent laws, enacted anew in 1852, and with them
the sole protection of the inventive talent and industry of the nation.
This naturally caused much excitement and interest among those chiefly
concerned, and a very numerous body of gentlemen associated themselves
together and formed an institute for the purpose mainly of resisting the
aggression and inculcating views more in accordance with true principles,
as well as for explaining what were the true relations of inventive genius
to the welfare of the state. He hoped to be able to show strong reasons
for this action, and for energetically following it up in the future.
Although on that evening there were many visitors present besides the
members of the institute, yet he thought the subject could be shown to be
of such national importance that it might justly engage the attention of
any assembly of Englishmen, to whatever mode of thought they might belong.
The institute had persistently done its work ever since its formation.
Sometimes it had failed to make itself heard, at others it had been more
successful in so doing; but the net result of its labors--and he did not
fear to claim it as mainly due to those labors--had been to propagate and
spread abroad a fact and a feeling entirely opposed to the false doctrines
previously current on the subject, namely, that among our most valuable
laws were those which could excite the intelligence and reward the labors
of the inventors of all nations. There were still those who wished to see
the patent laws swept away, but their numbers had dwindled into a
miserable minority, composed mainly of manufacturers who were so curiously
short-sighted as not to see that all improvement in manufactures must come
from inventive talent, or those who, still more blind, could not perceive
that property created by brains was certainly not a monopoly, and deserves
protection quite as much as any other form of possession, in order that it
may be developed by capital. He need scarcely waste time in pointing out
the fallacy of refusing to pay for the seed corn of industrial pursuits,
for that fallacy, bit by bit, had been completely swept away, and last
year the labors of the institute had been so far crowned with success that
the President of the Board of Trade, in his place in Parliament, announced
his conviction that "inventors were the creators of trade, and ought to be
encouraged and not repressed." Such a conviction, forced home in such a
quarter, ought to have produced a great and beneficial change in the
legislation on the subject, and the hopes of inventors were that this
would surely be the case; but when the bill appeared these hopes were
considerably depressed, and now, after a year's experience of the working
of the changed law, scarcely any benefit appears to have been obtained,
beyond the meager concession that the heavy payments demanded, for an
English patent may be made in installments instead of lump sums. Against
this infinitesimal concession had to be set a number of disabilities which
did not formerly exist, such as compulsory licenses, which disinclined the
capitalist to invest in inventions, attempts to assimilate the provisional
specification to the complete, or to restrict the latter within the terms
of the former, attempts to separate the parts of an invention, and thus
increase the number of patents required to protect it, and many other
minor annoyances which would take too much time to explain fully. It was
true that there was some extension of the time for payment--some such
locus penitentiæ as would be accorded to any debtor by any creditor in the
hope of getting the assets; but the promised spirit of encouragement to
inventors was not to be found in the bill; it was still a boon which must
be earnestly sought by the institute.
He had said that the concessions granted were almost infinitesimal, yet a
result had been obtained, surprisingly confirmatory of the views always
advocated by the institute as to the potentiality of the inventive talent
of this nation were it released from its shackles. While in former years
the highest number of patents taken out had slowly risen to the number of
five to six thousand per annum, in the year now expiring it had bounded to
more than three times five thousand--had at one leap reached an equality
with the patents of the United States, where only £4 ($20) was paid for a
patent for seventeen years, instead of £175, as in Great Britain, for a
term of fourteen years. If in the future we could hope to persuade the
legislators to be content with no heavier tax than in the United States
had yielded a heavy surplus over expenses of a well-conducted Patent
Office, he did not fear to assert that the number of patents taken out in
this country would again be trebled, and that trade and industry would be
correspondingly animated and developed. The result of the wiser patent law
of the United States had been to flood our markets with well-manufactured
yet cheap articles from that country which might have been equally well
made by our artisans at home had invention not been subject to such heavy
restrictions, and had technical skill been equally sure of its reward.
The business of the institute in the future was not to rest satisfied with
the proposition of Mr. Chamberlain, but to lead him or his successors
forward by logical and legitimate means toward the necessary corollary of
that proposition. If inventors were indeed the creators of trade, then the
President of the Board of Trade was bound to see, not only that they were
not prevented from creating trade, but that they received every facility
in performing their work. Hence all exertions should be used to convince
the Chancellor of the Exchequer that a less tax may produce a greater
income: to persuade the legal authorities that this description of
property, of all others, most deserves the protection of the law.
Inherited direct from the Giver of all good gifts, no person had been
dispossessed of anything he previously owned, and the wealth of humanity
might be indefinitely increased by means of it. Not many mighty, not many
noble, received this gift, but it was the inexhaustible heritage of the
humble, it was the rich reward of the intelligent of all races that
peopled the earth. To whomsoever given, this gift was intended to
contribute to the health and the wealth of the human race, for the
bringing into existence new products, for their utilization for the
encouragement of the general intelligence of the nations, and for the
lightening of the burdens of the poor. It would also cause technical
education to be more highly valued as a means to an end--for true
inventive genius was never so likely to succeed as when it passed from the
summit of the known to the confines of the possible, when, having learnt
and appreciated what predecessors had accomplished, it went earnestly to
work to solve the next problem, to remove the next obstacle on the path
which to them had proved insurmountable.
More beneficial than any other change whatever in our legislation would be
a full and cordial recognition, a complete and efficient protection, of
property created by thought. Then the humblest individual in the land
might have confidence that he could call into existence property not
inferior in value to that of the richest landowner, the most successful
merchant, or the most wealthy manufacturer, in the whole world. As an
instance of this Admiral Selwyn mentioned two prominent cases arising out
of the pursuit of two widely differing branches of knowledge, in the one
case by an outsider, in the other by a specialist. He referred to Sir H.
Bessemer, one of his valued colleagues in the vice-presidency of the
institute, and Mr. Perkins, the discoverer of aniline dyes. In each of
these instances, whatever might have been the results to the inventors,
and he hoped they had been satisfactory, a sum which might be estimated at
twenty millions sterling annually, constantly on the increase, and never
before existing, had been added to the income-tax-paying wealth of the
country. With such a result arising from the development of only two
inventions, he thought it would be seen that he must be a most ignorant,
foolish, or obstinate Chancellor of the Exchequer who would refuse to
allow such property to be created by requiring heavy preliminary payments,
or in any way discourage or fail to encourage to the utmost of his power
the creation of property which was capable of producing such a result--a
result which he would in vain seek for did he rely on landed property
alone, since this, in the hands of whomsoever it might be, never could
largely increase in extent, and was subject at this moment to serious
depreciation in tax-paying power.
The exertion of intelligence, combined with a sense of security in its
pecuniary results, was in itself opposed to loose notions of proprietary
rights, and tended to diminish that coveting of neighbors' goods which was
the fertile source of vice and crime, and which was capable of breaking
down the strongest and most wealthy community if indulged, till at last
society was resolved into its elements, and when nothing else was left as
property, man, the savage, coveted the scalp of his fellow man, and
triumphed over a lock of hair torn from his bleeding skull.
Invention was an ennobling pursuit, and was, even among those who were not
also handworkers, a means of employment which never left dull or idle
hours, while to the handworker it meant more, for it offered the most
ready means of rising among his fellows, and, where invention received
proper protection, of securing a competence for old age or ill health. Not
only, as he had before said, did the results of invention cause no loss to
any other individual, unless by displacing inferior methods of working,
but in most instances some distinct benefit arose to the whole human race,
and unless this was the case the patented invention failed to obtain
recognition, soon died out, and left the field clear for others to occupy.
He regretted that so few results had been obtained from the Patent Bill of
last year, but he would briefly refer to some of the changes thought
desirable by inventors and by the council of the institute.
No one could deem it desirable, it could scarcely be thought reasonable,
that an Englishman who was called upon to pay in the United States £7 for
a valid patent for seventeen years should be still obliged in his own
country to pay £175 for a less term of a patent which does not convey
anything but a right to go to law. It was also not reasonable to pretend
by a deed to convey a proprietary right while reserving the power to grant
compulsory licenses, which must tend to destroy the value of such
proprietary right.
It was a reproach to legislative perspicacity that the grantee of a patent
should be obliged to accept the view of the state, the grantor, as to the
value of the invention to the nation, and also that any other method of
proceeding to upset a patent, once granted, should be allowed than a suit
for revocation to the crown, on the ground of error, such revocation if
obtained not to prejudice the granting anew, with the old date, of a valid
patent for the parts of the invention which are not proved to be
anticipated at the trial. There are many other points which could not be
referred to on the present occasion, but he might say that the duty of the
council would be to press them forward until the capitalist could consider
patented property at least as sound an investment as any other. So might
the wealth of the nation be largely increased, and the sense of justice
between man and man be more fully inculcated. In the United States
inventors were able at once to secure the favorable attention of
capitalists, because there the whole business of the Patent Office was to
assist the inventor to obtain a valid--and, as far as possible, an
indisputable--patent.
Even so small an article as a pair of pliers, one of the most familiar of
tools, had been proved to be capable of patented improvement. Formerly
these were always made to open and close at an angle which precluded their
holding any object grasped by them with the desirable rigidity. A clever
workman invented a means of producing this effect by the application of a
parallel motion. He probably went to the office at Washington, was
referred to a certain room in a certain corridor, and there found a
gentleman whose business it was to know all about the patents for such
tools. By his aid he eliminated from his patent all anticipatory matter,
and issued from the office with a valid patent, which, developed by
capital, had supplied all the trades which employ such instruments with a
better means of accomplishing their work, had employed capital and labor
with remunerative results in producing the pliers, and had added one more
to the little things which create trade for his country.
This was a typical instance of the way in which invention was encouraged
in America. Why should it be otherwise here? For many years literary
property had received a protection which was yet to be desired for
patented invention. Not only for fourteen years, but for the duration of a
man's life, was that kind of brain property protected, and even after his
death his heirs still continued to derive benefit from it. Should a
romance or a poem be deemed more worthy of reward than the labors of those
inventors to whom he had referred, and which certainly produced far
greater and more abiding advantage to the nation? To secure a due
appreciation of the whole importance of invention, no other means could be
adopted than that which the institute had been formed to secure, namely,
the union of inventors, not only of one nation, but of the whole world.
The international character of the subject had been recognized by the
institute, and they had never neglected any opportunities of pressing that
view of the subject, which had at last obtained some recognition from our
government.
No great result could, however, be expected from a congress where
inventors, not lawyers or patent agents, still less officials trained in a
vicious routine, formed the majority. It might be hoped that next year
there would arise an opportunity for such a congress, and that the
institute would do its best to improve the occasion. There never had been
a time when England more required the creation of new industries. Our
agriculturists had signally failed to hold their own in the face of
unlimited competition, and the food of the nation no longer came from
within. But if that were the case, then some means must be found of paying
for the food imported from abroad, and this could only be done by constant
improvement in manufactures, or some change by which we might sell some of
our other productions at a profit if the food could not be produced but at
a loss. Here invention might fitly be called to aid, but could only
respond if all restrictions were removed and every facility granted.
Capital must be induced to consider that home investments are more
remunerative and not less secure than any others, and this could only be
done by adding to the security of the property proposed for investment. He
had referred to the unlimited nature of the property created by invention,
and they would infer that if properly protected there was equally no limit
to the capital that could be profitably employed in developing such
property. The institute did not exist solely or even mainly for the
purpose of advocating the claims of inventors to consideration, either
individually or collectively, but for the great object of forcing home
upon the convictions of the people the fact that at the very foundation of
the wealth and prosperity of every nation lies the intelligence, the
skill, the honesty, and the self-denial of its sons.
If, when these were exercised, for want of wise legislation such virtues
failed to secure their due reward, they sought a more genial clime, and
that nation which had undervalued them sank to rise no more; or, if the
error were acknowledged, and too late the course was reversed, found
itself already outstripped in the race of progress, and could slowly, if
ever, regain its lost position. Finally he urged the inventors of England
to rally round the institution in all their strength, and thus secure the
objects of which he had striven, however feebly, to point out the
importance. If they did so, this institution would take a rank second to
no other in the empire: and while acknowledging that the interests of the
inventor must always be subordinate to the welfare of the state, he
asserted that the two were inseparable, and that in no other way could the
latter and principal result be so completely secured as by according a due
consideration to the former.
* * * * *
THE NEW CENTRAL SCHOOL AT PARIS.
We present herewith, from _L'Illustration_, views of the amphitheater, and
first and second year laboratories of the new Central School at Paris.
[Illustration: THE NEW CENTRAL SCHOOL AT PARIS.]
The amphitheater does not perceptibly differ from those of other schools.
It consists of a semicircle provided with rows of benches, one above
another, upon which the pupils sit while listening to lectures and taking
notes thereof. Several blackboards, actuated by hydraulic motors, serve
for demonstration by the professor, who, if need be, will be enabled,
thanks to the electricity and gas put within his reach, to perform
experiments of various kinds. Electricity is brought to him by wires, just
as water and gas are by pipes. It will always be possible for him to
support the theory that he is explaining by experiments which facilitate
the comprehension of it by the pupils. The amphitheater is likewise
provided with a motor which furnishes the professor with power whenever he
has recourse to a mechanical application.
It will not be possible for the pupils to have their attention distracted
by what is going on outside of the amphitheater, since the architect has
taken the precaution to use ground glass in the windows.
[Illustration: THE NEW CENTRAL SCHOOL AT PARIS.]
As regards the laboratories, it is allowable to say that they constitute
the first great school of experimental chemistry in France. The first year
laboratory consists of a series of tables, provided with evaporating
hoods, at which a series of pupils will study general chemistry
experimentally. Electricity, and gas and water cocks are within reach of
each operator, and all the deleterious emanations from the acids that are
used or are produced in studying a body will escape through the hoods.
The third year laboratory is designed for making commercial analyses.
These latter are made by either dry or wet way. The first method employs
water chiefly as a vehicle, and alkaline solutions as reagents. The second
employs reagents in a dry state, and the action of which requires lamp and
furnace heat. The furnaces employed in the new school are like those
almost exclusively used industrially for the analysis of ores. The tables
upon which analyses by dry way are made are large enough to allow sixteen
pupils to work.
[Illustration: THE NEW CENTRAL SCHOOL AT PARIS.]
Analyses by wet way are made upon tables, with various sorts of vessels.
Along with water, gas, and electricity, the pupils have at their disposal
a faucet from whence they may draw the hydrosulphuric acid which is so
constantly used in laboratory operations.
The architect of the new school is Mr. Denfer.
* * * * *
[NATURE.]
RESEARCHES ON THE ORIGIN AND LIFE-HISTORIES OF THE LEAST AND LOWEST
LIVING THINGS.
By Rev. W.H. DALLINGER, LL. D.
To all who have familiarized themselves, even cursorily, with modern
scientific knowledge, it is well known that the mind encounters the
_infinite_ in the contemplation of minute as well as in the study of vast
natural phenomena. The farthest limit we have reached, with the most
gigantic standard of measurement we could well employ, in gauging the
greatness of the universe, only leaves us with an overwhelming
consciousness of the awful greatness--the abyss of the infinite--that lies
beyond, and which our minds can never measure. The indefinite has a limit
somewhere; but it is not the indefinite, it is the measureless, the
infinite, that vast extension forces upon our minds. In like manner, the
immeasurable in minuteness is an inevitable mental sequence from the facts
and phenomena revealed to us by a study of the _minute_ in nature. The
practical divisibility of matter disclosed by modern physics may well
arrest and astonish us. But biology, the science which investigates the
phenomena of all living things, is in this matter no whit behind. The most
universally diffused organism in nature, the least in size with which we
are definitely acquainted, is so small that fifty millions of them could
lie together in the one-hundredth of an inch square. Yet these definite
living things have the power of locomotion, of ingestion, of assimilation,
of excretion, and of enormous multiplication, and the material of which
the inconceivably minute living speck is made is a highly complex chemical
compound. We dare not attempt a conception of the minuteness of the
ultimate atoms that compose the several simple elements that thus
mysteriously combine to form the complex substance and properties of this
least and lowliest living thing. But if we could even measure these, as a
mental necessity, we are urged indefinitely on to a minuteness without
conceivable limit, in effect, a minuteness that is beyond all finite
measure or conception. So that, as modern physics and optics have enabled
us not to conceive merely, but to actually realize, the vastness of
spatial extension, side by side with subtile tenuity and extreme
divisibility of matter, so the labor, enthusiasm, and perseverance of
thirty years, stimulated by the insight of a rare and master mind, and
aided by lenses of steadily advancing perfection, have enabled the student
of life-forms not simply to become possessed of an inconceivably broader,
deeper, and truer knowledge of the great world of visible life, of which
he himself is a factor, but also to open up and penetrate into a world of
minute living things so ultimately little that we cannot adequately
conceive them, which are, nevertheless, perfect in their adaptations and
wonderful in their histories. These organisms, while they are the least,
are also the lowliest in nature, and are to our present capacity totally
devoid of what is known as organic structure, even when scrutinized with
our most powerful and perfect lenses. Now these organisms lie on the very
verge and margin of the vast area of what we know as living. They possess
the essential properties of life, but in their most initial state. And
their numberless billions, springing every moment into existence wherever
putrescence appeared, led to the question, How do they originate? Do they
spring up _de novo_ from the highest point on the area of _not-life_,
which they touch? Are they, in short, the direct product of some yet
uncorrelated force in nature, changing the dead, the unorganized, the
not-living, into definite forms of life? Now this is a profound question,
and that it is a difficult one there can be no doubt. But that it is a
question for our laboratories is certain. And after careful and prolonged
experiment and research the legitimate question to be asked is, Do we find
that, in our laboratories and in the observed processes of nature now, the
not-living can be, without the intervention of living things, changed into
that which lives?
To that question the vast majority of practical biologists answer without
hesitancy, _No_, we have no facts to justify such a conclusion. Prof.
Huxley shall represent them. He says: "The properties of living matter
distinguish it absolutely from all other kinds of things;" and, he
continues, "the present state of our knowledge furnishes us with no link
between the living and the not-living." Now let us carefully remember that
the great doctrine of Charles Darwin has furnished biology with a
magnificent generalization; one indeed which stands upon so broad a basis
that great masses of detail and many needful interlocking facts are, of
necessity, relegated to the quiet workers of the present and the earnest
laborers of the years to come. But it is a doctrine which cannot be
shaken. The constant and universal action of variation, the struggle for
existence, and the "survival of the fittest," few who are competent to
grasp will have the temerity to doubt. And to many, that lies within it as
a doctrine, and forms the fibre of its fabric, is the existence of a
continuity, an unbroken stream of unity running from the base to the apex
of the entire organic series. The plant and the animal, the lowliest
organized and the most complex, the minutest and the largest, are related
to each other so as to constitute one majestic organic whole. Now to this
splendid continuity practical biology presents no adverse fact. All our
most recent and most accurate knowledge confirms it. But _the_ question
is, Does this continuity terminate now in the living series, and is there
then a break--a sharp, clear discontinuity, and beyond, another realm
immeasurably less endowed, known as the realm of not-life? or Does what
has been taken for the clear-cut boundary of the vital area, when more
deeply searched, reveal the presence of a force at present unknown, which
changes not-living into the living, and thus makes all nature an unbroken
sequence and a continuous whole? That this is a great question, a question
involving large issues, will be seen by all who have familiarized
themselves with the thought and fact of our times. But we must treat it
purely as a question of science; it is not a question of _how_ life
_first_ appeared upon the earth, it is only a question of whether there is
any natural force _now_ at work building not-living matter into living
forms. Nor have we to determine whether or not, in the indefinite past,
the not-vital elements on the earth, at some point of their highest
activity, were endowed with, or became possessed of, the properties of
life.
[Illustration: Fig. 1]
On that subject there is no doubt. The elements that compose
protoplasm--the physical basis of all living things--are the familiar
elements of the world without life. The mystery of life is not in the
elements that compose the vital stuff. We know them all, we know their
properties. The mystery consists _solely_ in _how_ these elements can be
so combined as _to acquire_ the transcendent properties of life. Moreover,
to the investigator it is not a question of _by what means_ matter
dead--without the shimmer of a vital quality--became either slowly or
suddenly possessed of the properties of life. Enough for us to know that
whatever the power that wrought the change, that power was competent, as
the issue proves. But that which calm and patient research has to
determine is whether matter demonstrably _not living_ can be, without the
aid of organisms already living, endowed with the properties of life.
Judged of hastily, and apart from the facts, it may appear to some minds
that an origin of life from not-life, by sheer physical law, would be a
great philosophical gain, an indefinitely strong support of the doctrine
of evolution. If this were so, and, indeed, so far as it is believed to be
so, it would speak and does speak volumes in favor of the spirit of
science pervading our age. For although the vast majority of biologists in
Europe and America accept the doctrine of evolution, they are almost
unanimous in their refusal to accept as in any sense competent the reputed
evidence of "spontaneous generation;" which demonstrates, at least, that
what is sought by our leaders in science is not the mere support of
hypotheses, cherished though they may be, but the truth, the uncolored
truth, from nature. But it must be remembered that the present existence
of what has been called "spontaneous generation," the origin of life _de
novo_ to-day, by physical law, is by no means required by the doctrine of
evolution. Prof. Huxley, for example, says: "If all living beings have
been evolved from pre-existing forms of life, it is enough that a single
particle of protoplasm should _once_ have appeared upon the globe, as the
result of no matter what agency; any further independent formation of
protoplasm would be sheer waste." And why? we may ask. Because one of the
most marvelous and unique properties of protoplasm, and the living forms
built out of it, _is the power_ to multiply indefinitely and for ever!
What need, then, of spontaneous generation? It is certainly true that
evidence has been adduced purporting to support, if not establish, the
origin in dead matter of the least and lowest forms of life. But it
evinces no prejudice to say that it is inefficient. For a moment study the
facts. The organisms which were used to test the point at issue were those
known as _septic_. The vast majority of these are inexpressibly minute.
The smallest of them, indeed, is so small that, as I have said, fifty
millions of them, if laid in order, would only fill the one-hundredth part
of a cubic inch. Many are relatively larger, but all are supremely minute.
Now, these organisms are universally present in enormous numbers, and ever
rapidly increasing in all moist putrefactions over the surface of the
globe.
Take an illustration prepared for the purpose, and taken direct from
nature. A vessel of pure drinking water was taken during the month of July
at a temperature of 65 deg. F., and into it was dropped a few shreds of
fish muscle and brain. It was left uncovered for twelve hours; at the end
of that time a small blunt rod was inserted in the now somewhat opalescent
water, and a minute drop taken out and properly placed on the microscope,
and, with a lens just competent to reveal the minutest objects, examined.
The field of view presented is seen in Fig. 1, A. But--with the exception
of the dense masses which are known as zoogloea or bacteria, fused
together in living glue--the whole field was teeming with action; each
minute organism gyrating in its own path, and darting at every visible
point. The same fluid was now left for sixteen hours, and once more a
minute drop was taken and examined with the same lens as before. The field
presented to the eye is depicted in Fig. 1, B, where it is visible that
while the original organism persists yet a new organism has arisen in and
invaded the fluid. It is a relatively long and beautiful spiral form, and
now the movement in the field is entrancing. The original organism darts
with its vigor and grace, and rebounds in all directions. But the spiral
forms revolving on their axes glide like a flight of swallows over the
ample area of their little sea. Ten hours more elapsed and, without change
of circumstances, another drop was taken from the now palpably putrescent
fluid. The result of examination is given in Fig. 1, C, where it will be
seen that the first organism is still abundant, the spiral organism is
still present and active, but a new and oval form, not a bacterium, but a
_monad_, has appeared. And now the intensity of action and beauty of
movement throughout the field utterly defy description, gyrating, darting,
spinning, wheeling, rebounding, with the swiftness of the grayling and the
beauty of the bird. Finally, at the end of another eight to sixteen hours,
a final "dip" was taken from the fluid, and under the same lens it
presented as a field what is seen in Fig. 1, D, where the largest of the
putrefactive organisms has appeared and has even more intense and more
varied movements than the others. Now the question before us is, "How did
these organisms arise?" The water was pure; they were not discoverable in
the fresh muscle of fish. Yet in a dozen hours the vessel of water is
peopled with hosts of individual forms which no mathematics could number!
How did they arise? From universally diffused eggs, or from the direct
physical change of dead matter into living forms? Twelve years ago the
life-histories of these forms were unknown. We did not know biologically
how they developed. And yet with this great deficiency it was considered
by some that their mode of origin could be determined by heat experiments
on the adult forms. Roughly, the method was this: It was assumed that
nothing vital could resist the boiling point of water. Fluids, then,
containing full-grown organisms in enormous multitudes, chiefly bacteria,
were placed in flasks, and boiled for from five to ten minutes. While they
were boiling the necks of the flasks was hermetically closed; and the
flask was allowed to remain unopened for various periods. The reasoning
was: "Boiling has killed all forms of vitality _in_ the flask; by the
hermetical sealing nothing living can gain subsequent access to the fluid;
therefore, if living organisms do appear when the flask is opened, they
must have arisen in the dead matter _de novo_ by spontaneous generation,
but if they do never so arise, the probability is that they originate in
spores or eggs."
Now it must be observed concerning this method of inquiry that it could
never be final; it is incompetent by deficiency. Its results could never
be exhaustive until the life-histories of the organisms involved were
known. And further, although it is a legitimate method of research for
partial results, and was of necessity employed, yet it requires precise
and accurate manipulation. A thousand possible errors surround it. It can
only yield scientific results in the hands of a master in physical
experiment. And we find that when it has secured the requisite skill, as
in the hands of Prof. Tyndall, for example, the result has been the
irresistible deduction that living things have never been seen to
originate in not-living matter. Then the ground is cleared for the
strictly biological inquiry, How do they originate? To answer that
question we must study the life histories of the minutest forms with the
same continuity and thoroughness with which we study the development of a
crayfish or a butterfly. The difficulty in the way of this is the extreme
minuteness of the organisms. We require powerful and perfect lenses for
the work. Happily during the last fifteen years the improvement in the
structure of the most powerful lenses has been great indeed. Prior to this
time there were English lenses that amplified enormously. But an
enlargement of the image of an object avails nothing, if there be no
concurrent disclosure of detail. Little is gained by expanding the image
of an object from the ten-thousandth of an inch to an inch, if there be
not an equivalent revelation of hidden details. It is in this revealing
quality, which I shall call _magnification_ as distinct from
_amplification_, that our recent lenses so brilliantly excel. It is not
easy to convey to those unfamiliar with objects of extreme minuteness a
correct idea of what this power is. But at the risk of extreme simplicity,
and to make the higher reaches of my subject intelligible to all, I would
fain make this plain.
But to do so I must begin with familiar objects, objects used solely to
convey good relative ideas of minute dimension. I begin with small objects
with the actual size of which you are familiar. All of us have taken a
naked eye view of the sting of the wasp or honey bee; we have a due
conception of its size. This is the scabbard or sheath which the naked eye
sees.[3] Within this are two blades terminating in barbed points. The
point of the scabbard more highly magnified is presented, showing the
inclosed barbs. One of the barbs, looked at on the barbed edge, is also
seen. Now these two barbed stings are tubes with an opening in the end of
the barb. Each is connected with the tube of the sac, C. This Is a
reservoir of poison, and D is the gland by which it is secreted. Now I
present this to you, not for its own sake, but simply for the comparison,
a comparison which struck the earliest microscopists. Here is the scabbard
carefully rendered. One of the stings is protruded below its point, as in
the act of stinging; the other is free to show its form. Now the actual
length of this scabbard in nature was the _one-thirtieth_ of an inch. I
have taken the point, C, of a fine cambric sewing needle, and broken it
off to slightly less than the one-thirtieth of an inch, and magnified it
as the sting is magnified. Now here we obtain an instance of what I mean
by magnification. The needle point is not merely bigger, unsuspected
details start into view. The sting is not simply enlarged, but all its
structure is revealed. Nor can we fail to note that the _finish_ of art
differs from that of nature. The homogeneous gloss of the needle
disappears under the fierce scrutiny of the lens, and its delicate point
becomes furrowed and riven. But Nature's finish reveals no flaw, it
remains perfect to the last.
[Footnote 3: A magnified image of the bee's sting was projected on the
screen.]
We may readily amplify this. The butterflies and moths of our native lands
we all know; most of us have seen their minute eggs. Many are quite
visible to the unaided eye; others are extremely minute. A gives the egg
of the small white butterfly;[4] B, that of the small tortoiseshell; C,
that of the waved umber moth; D, that of the thorn moth; E, that of the
shark moth; at F we have the delicate egg of the small emerald butterfly,
and at G an American skipper; and finally, at H, the egg of a moth known
as mania maura. In all this you see a delicacy of symmetry, structure, and
carving, not accessible to the eye, but clearly unfolded. We may, from our
general knowledge, form a correct notion of the average relation in size
existing between butterflies and their eggs; so that we can compare. Now
there is a group of extremely minute, insect-like forms that are the
parasites of birds. Many of them are just plainly visible to the naked
eye, others are too minute to be clearly seen, and others yet again wholly
elude the unaided sight. The epizoa generally lodge themselves in various
parts of the plumage of birds; and almost every group of birds becomes the
host of some specific or varietal form with distinct adaptations. There is
here seen a parasite that secretes itself in the inner feathers of the
peacock, this is a form that attacks the jay, and here is one that
secretes itself beneath the plumage of the partridge.
[Footnote 4: A series of the eggs of butterflies were then shown, as were
the objects successively referred to, but not here reproduced.]
Now these minute creatures also deposit eggs. They are placed with
wonderful instinct in the part of the plumage and the part of the feather
which will most conserve their safety; and they are either glued or fixed
by their shape or by their spine in the position in which they shall be
hatched. I show here a group of the eggs of these minute creatures. I need
not call your attention to their beauty; it is palpable. But I am fain to
show you that, subtle and refined as that beauty is, it is clearly brought
out. The flower-like beauty of the egg of the peacock's parasite, the
delicate symmetry and subtle carving of the others, simply entrance an
observer. Note then that it is not merely _enlarged_ specks of form that
we are beholding, but such true magnifications of the objects as bring out
all their subtlest details. And it is _this_ quality that must
characterize our most powerful lenses. I am almost compelled to note in
passing that the _beauty_ of these delicate and minute objects must not be
considered _an end_--a purpose--in nature. It is not so. The form is what
it is because it _must be_ so to serve the end for which the egg is
formed. There is not a superfluous spine, not a useless petal in the
floral egg, not an unneeded line of chasing in the decorated shell. It is
shaped beautifully because its shape is needed. In short, it is Nature's
method; the identification of beauty and use. But to resume. We may at
this point continue our illustrations of the analytical power of moderate
lenses by a beautiful instance. We are indebted to Albert Michael, of the
Linnean Society of England, for a masterly treatise on a group of acari,
or _mites_, known as the _oribatidæ_. Many of these he has discovered. The
one before you is a full grown nymph of what is known as a _palmicinctum_.
It is deeply interesting as a form; but for us its interest is that it is
minute, being only a millimeter in length. But it repeatedly casts the
dorsal skin of the abdomen. Each skin is bordered by a row of exquisite
scales; and then successive rows of these scales persist, forming a
protection to the entire organism. Mark then that we not only reveal the
general form of the nymph, but the lens reveals the true structure of the
scales, not enlargement merely, but detail. The egg of the organism, still
more magnified, is also seen.
To vary our examples and still progress. We all know the appearance and
structure of chalk. The minute foraminifera have, by their accumulated
tests, mainly built up its enormous masses. But there is another chalk
known as Barbados earth; it is silicious, and is ultimately composed of
minute and beautiful skeletons such as those which, enormously magnified,
you now see. These were the glassy envelopes which protected the living
speck that dwelt within and built it. They are the minutest of the
Radiolaria, which peopled in inconceivable multitudes the tertiary oceans;
and, as they died, their minute skeletons fell down in a continuous rain
upon the ocean bed, and became cemented into solid rock which geologic
action has brought to the surface in Barbados and many other parts of the
earth. If a piece of this earth, the size of a bean, be boiled in dilute
acid and washed, it will fall into powder, the ultimate grains of which
are such forms as these which you see. The one before you is an instance
of exquisite refinement of detail. The form from which the drawing of the
magnified image was made was extremely small--a mere white speck in the
strongest light upon a black ground. But you observe it is not a speck of
form merely enlarged. It is not merely beauty of outline made bigger. But
there is--as in the delicate group you now see--a perfect opening up of
otherwise absolutely invisible details. We may strengthen this evidence in
favor of the analytical power of our higher lenses by one more _familiar_
example, and then advance to the most striking illustration of this power
which our most perfect and powerful lenses can afford. I fear that may be
taking too much for granted to assume that every one in an audience like
this has seen a human flea! Most, however, will have a dim recollection or
suggestive instinct as to its size in nature. Nothing striking is revealed
by this amount of magnification excepting the existence of breathing pores
or spiracles along the scale armor of its body. But there is a trace of
structure in the terminal ring of the exo-skeleton which we cannot clearly
define, and of which we may desire to know more. This can be done only by
the use of far higher powers.
To effect this, we must carefully cut off this delicate structure, and so
prepare it that we may employ upon it the first of a series of our highest
powers. The result of that examination is given here.[5] You see that the
whole organ has a distinct form and border, and that its carefully carved
surface gives origin to wheel-like areolæ which form the bases of delicate
hairs. The function of this organ is really unknown. It is known from its
position as the _pygidium_; and from the extreme sensitiveness of the
hairs to the slightest aerial movement, may be a tactile organ warning of
the approach of enemies; the eyes have no power to see. But we have not
reached the ultimate accessible structure of this organ. If we place a
portion of the surface under one of the finest of our most powerful
lenses, this will be the result.[6] Now, without discussing the real
optical or anatomical value of this result as it stands, what I desire to
remind you of is:
1. The natural size of the flea.
2. The increase of knowledge gained by its general enlargement.
3. The relation in size between the flea and its pygidium.
4. The manner in which our lenses reveal its structure, not merely amplify
its form.
[Footnote 5: The pygidium of the flea, very highly magnified, was here
shown.]
[Footnote 6: An illustration of the pygidium structure seen with
one-thirty-fifth immersion was given.]
Now with these simple and yet needful preliminaries you will be able to
follow me in a careful study of the least, the very lowliest and smallest,
of all living things. It lies on the very verge of our present powers of
optical aid, and what we know concerning it will convince you that we are
prepared with competent skill to attack the problem of the life-histories
of the smallest living forms. The group to which the subject of our
present study belongs is the bacteria. They are primarily staff-like
organisms of extreme minuteness, but may be straight, or bent, or curved,
or spiral, or twisted rods. This entire projection is drawn on glass, with
_camera lucida_, each object being magnified 2,000 diameters, that is to
say, 4,000,000 of times in area. Yet the entire drawing is made upon an
area of not quite 3 inches in diameter, and afterward projected here. The
objects therefore are all equally magnified, and their relative sizes may
be seen. The giant of the series is known as _Spirillum volutans;_ and you
will see that the representative species given become less and less in
size until we reach the smallest of all the definite forms, and known to
science as _Bacterium termo_.
Now within given limits this organism varies in size, but if a fair
average be taken its size is such that 50,000,000 laid in order would only
fill the hundredth of a cubic inch. Now the majority of these forms _move_
with rapidity and grace in the fluids they inhabit. But how? By what
means? By looking at the largest form of this group, you will see that it
is provided with two delicate fibers, one at each end. Ehrenberg and
others strongly suspected their existence, and we were enabled, with more
perfect lenses, to _demonstrate_ their presence some twelve years ago.
They are actually the swimming organs of this Spirillum. The fluid is
lashed rhythmically by these fibers, and a spiral movement of the utmost
grace results. Then do the intermediate forms that move also possess these
flagella, and does this least form in nature, viz., _Bacterium termo_,
accomplish its bounding and rebounding movements in the same way? Yes! by
a series of resolute efforts, in using a new battery of lenses--the finest
that at that time had ever been put into the hands of man--I was enabled
to show in succession that each motile form of Bacterium up to _B.
lineola_ accomplished its movements by fibers or flagella; and that in the
act of self-division, constantly taking place, a new fiber was drawn out
for each half before separation.
But the point of difficulty was _B. termo_. The demonstration of its
flagella was a task of difficulty which only patient purpose could
conquer. But by the use of our new lenses, and special illumination we--my
colleague and I--were enabled to demonstrate clearly a flagellum at each
end of this least of living organisms, as you see, and by the rapid
lashing of the fluid, alternately or together, with these flagella, the
powerful, rapid, and graceful movements of this smallest known living
thing are accomplished. Of course these fibers are inconceivably
fine--indeed for this very reason it was desirable, if possible, to
_measure_ it, to discover its actual thickness. We all know that, both for
the telescope and the microscope, beautiful apparatus are made for
measuring minute magnified details. But unfortunately no instrument
manufactured was delicate enough to measure _directly_ this fiber. If it
were measured it must be by an indirect progress, which I accomplished
thus: The diameter of the body of _B. termo_, _i.e._, from; side to side,
may in different forms vary from the 1/20000 to the 1/50000 of an inch.
_That_ is a measurement which we may easily make directly with a
micrometer. Haying ascertained this, I determined to discover the ratio of
thickness between the body of the Bacterium and its flagellum--that is to
say, to discover how many of the flagella laid side by side would make up
the width of the body.
I proceeded thus: This is a complicated microscope placed on a tripod, so
arranged that it may be conveniently worked upright. There is a special
instrument for centering and illuminating. On the stage of the instrument,
the Bacterium with its flagellum in distinct focus is placed. Instead of
the simple eyepiece, _camera lucida_ is placed upon it. This instrument is
so constructed that it appears to throw the image of the object upon the
white sheet of paper on the small table at the right hand where the
drawing is made, at the, same time that it enables the same eye to see
the pencil and the right hand. In this way I made a careful drawing of _B.
termo_ and its flagellum, magnified 5,000 diameters. Here is a projection
of the drawing made. But I subsequently avoided paper, and used under the
camera most carefully prepared surface of ground glass. When the drawing
was made I placed on the drawing a drop of Canada balsam, and covered it
with a circle of thin glass, just like any other microscopic mounted
object. This is a micro-slide so prepared. Now you can see that I only
have to lay this on the stage of a microscope, make it an object for a low
power, and use a screw micrometer to find how many flagella go to the
making of a body. The result is given in the figure; you see that ten
flagella would fill the area occupied by the diameter of the body.
In the case chosen the body was the 1/20,400 of an inch wide, and
therefore, when divided by ten, gave for the flagellum a thickness of the
1/204,000 of an English inch. In the end I made fifty separate drawings
with four separate lenses. I averaged the result in each fifty, and then
took the average of the total of 200, and the mean value of the width of
the flagellum was the 1/204,700 of an English inch. It will be seen, then,
that we are possessed of instruments which, when competently used, will
enable us to study the life-histories of the putrefactive organisms,
although they are the minutest forms of life. I have stated that they were
the inevitable accompaniments of putrescence and decay. You learned from a
previous illustration the general appearance of the Bacteria; they are the
earliest to appear whenever putrefaction shows itself. In fact the pioneer
is this--the ubiquitous _Bacterium termo._ The order of succession of the
other forms is by no means certain. But whenever a high stage of
decomposition is reached, a group of forms represented by these three will
swarm the fluid. These are the Monads, they are strictly putrefactive
organisms, they are midway in size between the least and largest Bacteria,
and are, from their form and other conditions, more amenable to research,
and twelve years ago I resolved, with the highest power lenses and
considerable practice in their use, to attack the problem of their origin;
whether as physical products of the not-living, or as the natural progeny
of parents.
But you will remember that only a minute drop of fluid containing them can
be examined at one time. This minute drop has to be covered with a minute
film of glass not more than the 1/200 of an inch thick. The highest lenses
are employed, working so near as almost to touch the delicate cover.
Clearly, then, the film of fluid would rapidly evaporate and cause the
destruction of the object studied. To prevent this an arrangement was
devised by which the lens and the covered fluid under examination were
used in an air-tight chamber, the air of which was kept in a saturated
condition; so that being, like a saturated sponge, unable to take in any
more, it left the film of fluid unaffected. But to make the work efficient
I soon found that there must be a second observer. Observation by leaps
was of no avail. To be accurate it must be unbroken. There must be no gap
in a chain of demonstration. A thousand mishaps would occur in trying to
follow a single organism through all the changes of successive hours to
the end. But, however many failures, it was evident, we must begin on
another form at the earliest point again, and follow it to the close. I
saw soon that every other method would have been merely empirical, a mere
piecemeal of imagination and fact. When one observer's ability to continue
a long observation was exhausted, there must be another at hand to take up
the thread and continue it; and thus to the end. I was fortunate indeed at
this time in securing the ready and enthusiastic aid of Dr. J.J. Drysdale,
of Liverpool, who practically lived with me for the purpose, and went side
by side with me to the work. We admitted nothing which we had not both
seen, and we succeeded each other consecutively, whenever needful, in
following to the end the complete life-histories of six of these
remarkable forms.
I will now give you the facts in relation to two which shall be typical.
We obtained them in enormous abundance in a maceration of fish. I will not
take them in the order of our researches, but shall find it best to
examine the largest and the smallest. The appearance of the former is now
before you. It is divergent from the common type when seen in its perfect
condition, avoiding the oval form, but it resumes it in metamorphosis. It
is comparatively huge in its proportions, its average extreme length being
the 1/1000 of an inch. Its normal form is rigidly adhered to as that of a
rotifer or a crustacean. Its body-substance is a structureless sarcode.
Its differentiations are a nucleus-like body, not common to the monads;
generally a pair of dilating vacuoles, which open and close, like the
human eyelid, ten to twenty times in every minute; and lastly, the usual
number of four flagella. That the power of motion in these forms and in
the Bacteria is dependent upon these flagella I believe there can be no
reasonable doubt. In the monads, the versatility, rapidity, and power of
movement are always correlated with the number of these. The one before us
could sweep across the field with majestic slowness, or dart with
lightning swiftness and a swallow's grace. It could gyrate in a spiral, or
spin on its axis in a rectilinear path like a rifled bullet. It could dart
up or down, and begin, arrest, or change its motion with a grace and power
which at once astonish and entrance. Fixing on one of these monads then,
we followed it doggedly by a never-ceasing movement of a "mechanical
stage," never for an instant losing it through all its wanderings and
gyrations; We found that in the course of minutes, or of hours, the
sharpness of its outline slowly vanish, its vacuoles disappeared, and it
lost its sharp caudal extremity, and was sluggishly amoeboid. This
condition tensified, the amoeboid action quickened as here depicted, the
agility of motion ceased, the nucleus body became strongly developed, and
the whole sarcode was in a state of vivid and glittering action.
If now it be sharply and specially looked for, it will be seen that the
root of the flagella _splits_, dividing henceforth into two separate
pairs. At the same moment a motion is set up which pulls the divided pairs
asunder, making the interval of sarcode to grow constantly greater between
them. During this time the nuclear body has commenced and continued a
process of self-division; from this moment the organism grows rapidly
rounder, the flagella swiftly diverge. A bean-like form is taken; the
nucleus divides, and a constriction is suddenly developed; this deepens;
the opposite position of the flagella ensues, the nearly divided forms
now vigorously pull in opposite directions, the constriction is thus
deepened and the tail formed. The fiber of sarcode, to which the
constricted part has by tension been reduced, now snaps, and two organisms
go free. It will have struck you that the new organism enters upon its
career with only _two_ flagella, and the normal organism is possessed of
four. But in a few minutes, three or four at most, the full complement
were always there. How they were acquired it was the work of months to
discover, but at last the mystery was solved. The newly-fissioned form
darted irregularly and rapidly for a brief space, then fixed itself to the
floor or to a rigid object by the ends of its flagella, and, with its body
motionless, an intense vibratory action was set up along the entire length
of these exquisite fibers. Rapidly the ends split, one-half being in each
fiber set free, and the other remaining fixed, and in 130 seconds each
entire flagellum was divided into a perfect pair.
Now the amoeboid state is a notable phenomenon throughout the monads as
precursive of striking change. It appears to subserve the purpose of the
more facile acquisition and digestion of food at a crisis. And this
augmented the difficulty of discovering further change; and only
persistent effort enabled us to discover that with comparative rareness
there appeared a form in an amoeboid state that was unique. It was a
condition chiefly confined to the caudal end, the sarcode having became
diffluent, hyaline, and intensely rapid in the protrusion and retraction
of its substance, while the nuclear body becomes enormously enlarged.
These never appear alone; forms in a like condition are diffused
throughout the fluid, and may swim in this state for hours. Meanwhile, the
diffluence causes a spreading and flattening of the sarcode and swimming
gives place to creeping, while the flagella violently lash. In this
condition two forms meet by apparent accident, the protrusions touch, and
instant fusion supervenes. In the course of a few seconds there is no
disconnected sarcode visible, and in five to seven minutes the organism is
a union of two of the organisms, the swimming being again resumed, the
flagella acting in apparent concert. This may continue for a short time,
when movement begins to flag and then ceases. Meanwhile, the bodies close
together, and the eyenots or vacuoles melt together, the two nuclei become
one and disappear, and in eighteen hours the entire body of "either has
melted into other," and a motionless, and for a time irregular, sac is
left. This now becomes smooth, spherical, and tight, being fixed and
motionless. This is a typical process; but the mingled weariness and
pleasure realized in following such a form without a break through all the
varied changes into this condition is not easily expressed.
But now the utmost power of lenses, the most delicate adjustment of light,
and the keenest powers of eyesight and attention must do the rest. Before
the end of six hours the delicate glossy sac opens gently at one place,
then there streams out a glairy fluid densely packed with semi-opaque
granules, just fairly visible when their area was increased six millions
of times, and this continued until the whole sac was empty and its entire
contents diffused. To follow with our utmost powers these exquisite specks
was an unspeakable pleasure, a group seen to roll from the sac, when
nearly empty, were fixed and never left. They soon palpably changed by
apparent swelling or growth, but were perfectly inactive; but at the end
of three hours a beaked appearance was presented. Rapid growth set in, and
at the end of another hour, how has entirely baffled us, they acquired
flagella and swam freely; in thirty-five minutes more they possessed a
nucleus and rapidly developed, until at the end of nine hours after
emission a sporule was followed to the parent condition and left in the
act of fission. In this way, with what difficulties I need not weary you,
a complete life-cycle was made out.
And now I will invite your attention to the developmental history of the
_most minute_ of the six forms we studied. In form it is a long oval, it
is without visible structure or differentiation within, and is possessed
of only a single flagellum. Its utmost length is the 1/5000 of an inch.
Its motion is continuous in a straight line, and not intensely rapid, nor
greatly varied, being wholly wanting in curves and dartings. The
copiousness of its increase was, even to our accustomed eyes, remarkable
in the extreme, but the reason was discovered with comparative ease. Its
fission was not a division into two, but into many. The first indication
of its approach in following this delicate form was the assumption rapidly
of a rounder shape. Then followed an amoeboid and uncertain form, with
an increased intensity of action which lasted a few moments, when
lassitude supervened, then perfect stillness of the body, which is now
globular in form, while the flagellum feebly lashed, and then fell upon
and fused with the substance of the sarcode. And the result is a solid,
flattened, homogeneous ball of living jelly.
To properly study this in its further changes, a power of from three to
four thousand diameters must be used, and with this I know of few things
in the whole range of minute beauty more beautiful than the effect of what
is seen. In the perfectly motionless flattened sphere, without the shimmer
of premonition and with inconceivable suddenness, a white cross smites
itself, as it were, through the sarcode. Then another with equal
suddenness at right angles, and while with admiration and amazement one
for the first time is realizing the shining radii, an invisible energy
seizes the tiny speck, and fixing its center, twists its entire
circumference, and endows it with a turbined aspect. From that moment
intense interior activity became manifest. Now the sarcode was, as it
were, kneading its own substance, and again an inner whirling motion was
visible, reminding one of the rush of water round the interior of a hollow
sphere on its way to a jet or fountain. Deep fissures or indentations
showed themselves all over the sphere; and then at the end of ten or more
minutes all interior action ceased, and the sphere had segmented into a
coiled mass. There was no trace of an investing membrane; the constituent
parts were related to each other simply as the two separating parts of an
ordinary fission; and they now commenced a quick, writhing motion like a
knot of eels, and then, in the course of from seven to thirty minutes,
separated, and fully endowed with flagella swam freely away, minute but
perfect forms, which by the rapid absorption of pabulum attained speedily
to the parent size.
It is characteristic of this group of organic forms that multiplication
by self-division is the common and continuous method of increase. The
other and essential method was comparatively rare and always obscure. In
this instance, on the first occasion the continuous observation of the
same "field" for five days failed to disclose to us any other method of
increase but this multiple-fission, and it was only the intense
suggestiveness of past experience that kept us still alert and prevented
us from inferring that it was the _only_ method. But eventually we
perceived that while this was the prevailing phenomenon, there were
scattered among the other forms of the same monad _larger_ than the rest,
and with a singular granular aspect toward the flagellate end. It may be
easily contrasted with the normal or ordinary form. Now by doggedly
following one of these through all its wanderings a wholly new phase in
the morphology of the creature was revealed. This roughened or granular
form seized upon and fastened itself to a form in the ordinary condition.
The two swam freely together, both flagella being in action, but it was
shortly palpable that the larger one was absorbing the lesser. The
flagellum of the smaller one at length moved slower, then sluggishly, then
fell upon the sarcode, which rapidly diminished, while the bigger form
expanded and became vividly active until the two bodies had actually fused
into one. After this its activity diminished, in a few minutes the body
became quite still, leaving only a feeble motion in the flagellum, which
soon fell upon the body-substance and was lost. All that was left now was
a still spheroidal glossy speck, tinted with a brownish yellow. A
peculiarity of this monad is the extreme uncertainty of the length of time
which may elapse before even the most delicate change in this sac is
visible. Its absolute stillness may continue for ten or more hours. During
this time it is absolutely inert, but at last the sac--for such it
is--opens gently, and there is poured out a brownish glairy fluid. At
first the stream is small, but at length its flow enlarges the rift in the
cyst, and the cloudy volume of its contents rolls out, and the hyaline
film that inclosed it is all that is left.
The nature of the outflow was like that produced by the pouring of strong
spirit into water. But no power that we could employ was capable of
detecting a _granule_ in it. To our most delicate manipulation of light,
our finest optical appliances, and our most riveted attention, it was a
homogeneous fluid and nothing more. This for a while baffled and disturbed
us. It lured us off the scent. We inferred that it might possibly be a
fertilizing fluid, and that we must look in other directions for the
issue. But this was fruitless, and we were driven again to the old point,
and having once more obtained the emitted fluid, determined to fix a lens
magnifying 5,000 diameters upon a clear space over which the fluid had
rolled, and near to the exhausted sac, and ply our old trade of _watching_
with unbroken observation.
The result was a reward indeed. At first the space was clear and white,
but in the course of a hundred minutes there came suddenly into view the
minutest conceivable specks. I can only compare the coming of these to the
growth of the stars in a starless space upon the eye of an intense watcher
in a summer twilight. You knew but a few minutes since a star was not
visible there, and now there is no mistaking its pale beauty. It was so
with these inexpressibly minute sporules; they were not there a short time
since, but they grew large enough for our optical aids to reveal them, and
there they were. Such a field after one hour's watching I present to you.
And here I would remark that these delicate specks were unlike any which
we saw emerge directly from the sac as granules. In that condition they
were always semi-opaque, but here they were transparent, and a brown
yellow, the condition always sequent upon a certain measure of growth.
To follow these without the loss of an instant's vision was pleasure of
the highest kind. In an hour and ten minutes from their first discovery
they had grown to oval points. In one hour more the specks had become
beaked and long. And this pointed end was universally the end from which
the flagellum emerged. With the flagellum comes motion, and with that
abundant pabulum, and therefore rapid growth. But when motion is attained
we are compelled to abandon the mass and follow one in all its impetuous
travels in its little world; and by doing so we are enabled to follow the
developed speck into the parent condition and size, and not to leave it
until it had, like its predecessors, entered on and completed its
wonderful self-division by fission.
It becomes then clearly manifest that these organisms, lowly and little as
they are, arise in fertilized parental products. There is no more caprice
in their mode of origin than in that of a crustacean or a bird. Their
minuteness, enormous abundance, and universal distribution is the
explanation of their rapid and practically ubiquitous appearance in a
germinating and adult condition. The presence of putrefiable or putrescent
matter determines at once the germination of the always-present spore. But
a new question arises. These spores are definite products. In the face of
some experimental facts one was tempted to inquire: Have these spores any
capacity to resist heat greater than the adults? It was not easy to
determine this question. But we at length were enabled to isolate the
germs of seven separate forms, and by means of delicate apparatus, and
some twelve months of research, to place each spore sac in an apparatus so
constructed that it could be raised to successive temperatures, and
without any change of conditions examined on the stage of the microscope.
In this way we reached successive temperatures higher and higher until the
death point--the point beyond which no subsequent germination ever
occurred--was reached in regard to _each_ organism. The result was
striking. The normal death point for the adult was 140° F. One of the
monads emitted from its sac minute mobile specks--evidently living
bodies--which rapidly grew. These we always destroyed at a temperature of
180° F. Three of the sacs emitted spores that germinated at every
temperature under 250° F. Two more only had their power of germination
destroyed at 260° F. And one, the least of all the monad forms, in a heat
partially fluid and partially dry, at all points up to 300° F. But if
wholly in fluid it was destroyed at the point of 290° F. The average being
that the power of heat resistance in the spore was to that of the adult
as 11 to 6. From this it is clear that we dare not infer spontaneous
generation after heat until we know the life-history of the organism.
In proof of this I close with a practical case. A trenchant and resolute
advocate of the origin of living forms _de novo_ has published what he
considers a crucial illustration in support of his case. He took a strong
infusion of common cress, placed it in a flask, boiled it, and, while
boiling, hermetically sealed it. He then heated it up in a digester to
270° F. It was kept for nine weeks and then opened, and, in his own
language, on microscopical examination of the earliest drop "there
appeared more than a dozen very active monads." He has fortunately
measured and roughly drawn these. A facsimile of his drawing is here. He
says that they were possessed of a rapidly moving lash, and that there
were other forms without tails, which he assumed were developmental stages
of the form. This is nothing less than the monad whose life-history I gave
you last. My drawings, magnified 2,500 diams., of the active organism and
the developing sac are here.
Now this experimenter says that he took these monads and heated them to a
temperature of about 140° F., and they were all absolutely killed. This is
accurately our experience. But he says these monads arose in a closed
flask, the fluid of which had been heated up to 270° F. Therefore, since
they are killed at 140° F., and arose in a fluid after being heated to
270° F., they must have arisen _de novo!_ But the truth is that this is
the monad whose spore only loses its power to germinate at a temperature
(in fluid) of 290°, that is to say, 20° F. higher than the heat to which,
in this experiment, they had been subjected. And therefore the facts
compel the deduction that these monads in the cress arose, not by a change
of dead matter into living, but that they germinated naturally from the
parental spore which the heat employed had been incompetent to injure.
Then we conclude with a definite issue, viz., by experiment it is
established that living forms do not now arise in dead matter. And by
study of the forms themselves it is proved that, like all the more complex
forms above them, they arise in parental products. The law is as ever,
only that which is living can give origin to that which lives.
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